Mileage Chart Calculated One-Way: Fill & Download for Free

A bus based rapid transit system is more efficient short term. A metro rail system will be more efficient and eco friendly long term (after 3-4 years), if its electricity is supplied from environment friendly sources.Before explaining how the answer was arrived at, let me get the assumptions and the scope of this question out of the way. When considering the term "efficiency" for transporting people using different modes, the following factors have to be considered:Efficiency at transporting passengers: Number of passengers transported per dedicated lane, per unit timeEnergy efficiency: Carbon footprint of the transportation mode and setting up of infrastructureEconomical efficiency: Cost of infrastructure, energy source and maintenance that affects the cost of travelTo model this scenario faster, I am making the assumption that transportation of people is same as a computer network or a series of pipes. People are analogous to packets in a network or fluid through pipes. This eliminates lot of other calculations (at least 15-20 variables that I can think of) required to perform an analysis of real world traffic, while still maintaining accuracy to a reasonable degree. I am also comparing the carbon footprint of the different mediums so that a fossil fuel vehicle can be compared to a electric vehicle. Finally, all scenarios are the "cruise stage" of a vehicle where it is most efficient in terms of fuel efficiency, aerodynamic drag etc. Since the calculations are redundant and this is a matter of debate in many forums, I have included a motorcycle, a gasoline fuel car, a hybrid, an electric and an SUV as well, for comparison. I will try keeping this as simple as I can using the charts alone, the spreadsheet is below for those interested in the full details. Other than the initial data like length, width, motor rating, mileage to the gallon and passenger capacity (sourced from manufacturer website or Wikipedia), all calculations are done from scratch to maintain accuracy. I have compared the efficiency of all the transportation modes over a length of 100 kilometers, so extrapolate the base results as required.Efficiency at transporting passengers / Passenger throughput:Passenger throughput is the number of passengers transported per lane per unit time. In simple words, how many passengers can the system move? Factors that affect this are:Passenger density (no of passengers per unit area)Cruise speed (speed at which fuel efficiency is maximum)Traffic density (degree of utilization of the lane)1.Passenger density:Passenger density is the number of people that can be transported per square meter of space available. It can be calculated by comparing the floor plans. For a bus, I am considering the ubiquitous Volvo chassis, used all over the world:As an equivalent to the Volvo in a metro system, I am considering the R143 built by Kawasaki, used in NYC Subway:The results for passenger density (higher is better) are as below:Trains have the highest passenger density of 2.9 passengers per square meterCruise speed:Though any vehicle is capable of high speeds, efficiency is maximum at the cruise speed where the factors like engine efficiency, drag, etc come together. The cruise speed (higher is better) of the different vehicles are:Traffic Density:Traffic does not denote conventional traffic here. It refers to how efficiently a lane is used. For example, there might be a train every 2 minutes or a train every hour. Distribution of traffic affects how many passengers can use the network. So traffic density is also a factor to be considered. If traffic density is 100%, that means that the lanes are utilised fully - maximum passengers are boarding an unlimited number of vehicles and moving at the cruise speed.Passenger throughput:As assumed earlier, consider a 100 km stretch of lane(s) for each of the transport medium. Only other vehicles of the same type and speed are allowed, so that there is no hindrance in their movement. To calculate the throughput, the number of passengers in the lane at any given point of time and the number of passengers who reach their destination are to be calculated. This is similar to volumetric flow rate of fluids, which is given by:(change in volume and change in time are parameters)The passengers mid way in the lane are eliminated for consideration. The size comparison of all the transportation modes are:The passenger throughput for each of the transportation medium, is a pretty big dataset, so I am considering one particular case- passenger occupancy 60%, traffic density 30%. The lane width is 3.5 meters for vehicles and 4 meters for metro trains. So the passenger throughput (higher is better) is:Trains are more more efficient at transporting people per lane - 153000 passengers an hour.Energy Efficiency:Energy efficiency of a particular transportation mode depends on two main factors:1.the vehicle/ engine efficiency2.the support infrastructureMost studies I have come across neglect factor 2, which introduces a huge bias. For instance, when comparing an aircraft and a train for green credits, tail pipe emissions alone are considered. This method is flawed as trains require laying of tracks and maintenance activities performed on them, whereas aircraft need only the runway and the aircraft to be maintained. This becomes more significant when the plane is making a trans Atlantic flight. So applying the same to a bus/train comparison, a bus needs a road to run efficiently whereas a metro train usually runs underground with reinforced concrete floors and steel columns. Since green credits and energy efficiency are dependent on these too, I have included these as well for fair comparison.Carbon foot print of the vehicle:Carbon foot print is considered because the vehicles use different types of fuel. Motorcycles and cars use gasoline, whereas a bus uses diesel. Trains and electric cars use electricity. So the carbon emitted due to the use of the vehicle can be used to compare all these different transportation modes. Electricity comes from different sources with different carbon footprints, so for every 1Watt consumed at the socket, the power comes from different sources. The world wide distribution of these sources are:Considering these parameters and the miles to a gallon, the carbon emission per passenger (lower is better) for these different modes over a 100KM stretch is:Few surprises here - Prius is the most economical personal vehicle, whereas trains and buses are close in terms of mass transport. Trains however have a edge of 250 grams of CO2 for every 100 KM.Infrastructure related Carbon Footprint:Infrastructure carbon footprint includes CO2 generated in the manufacture of the raw materials, construction of the infrastructure, transport of materials to the construction site etc. In several studies, this crucial and large contributor to efficiency is not included. Roads, bridges and every structure in the road use concrete. CO2 per ton of Concrete is in a ratio of 0.9:1 in many cases, and concrete manufacturing contributes to about 7% of world CO2 emissions. By this criteria, roads win hands down by a factor of 1300% initially. Trains catch up with the 250 grams of CO2 per 100 KM I had mentioned earlier for every passenger transported. After transporting a million passengers a day for 2 years in the case of overhead tracks or 10 million passengers a day for 3 years in the case of underground metro (by my estimates) they start being carbon footprint negative compared to buses. Consider the cross section of a underground metro system:For an over head metro system, the cross section is as below:Considering these three cases, the carbon footprint for these infrastructures (lower is better) are as below:When including the infrastructure, Buses are the most efficient transportation medium.Economical efficiency:Economically, the cost for transporting a passenger is lowest for a train car. The Prius comes second. So the results for economical efficiency is:For a metro train system, it saves 0.28$ per passenger. So if the system transports 10 million passengers a day, it will be recovering/paying for the initial investment after a period of 3.61 years to justify the extra investment.So to summarize, comparing all the statistics together, we get:A bus based transit system is efficient for a period of 3-4 years, after which a light metro system starts yielding more returns (and efficiency) in terms of carbon emissions, cost per passenger and transporting people. This comparison is for a 100 KM length of a lane, factors like cost of infrastructure are to be extrapolated based on the distance of travel.Trivia: The scenario described in the question actually exists in real life. In Sao Paolo (Brazil), buses have dedicated lanes (250 kms of them) and nearly 10 million people (the equivalent of everyone in Cuba) use it everyday, so my statement that buses are more efficient has some real world backing to it. Here is a picture of buses using dedicated lanes in Sao Paolo:Disclaimer - This is a question with lots of assumptions, and I have tried to answer it to closely match real world problems. It is however just that - a simple analysis for fun and information, calculated over a few hours. Recheck the numbers yourself if you are using it for any REAL study. The values of infrastructure calculations are assumptions using concrete alone, so I expect the values to be off (smaller) by a large margin. The passenger density is dependent on many other factors like commuter preference, country etc. I do not accept any responsibility for errors in the calculations or gotchas which may arise(they usually do). You can find all calculations, and methods used here:https://docs.google.com/spreadsheet/ccc?key=0Apdx0nQx0TirdHhvWGdGNVhFVWJPLV8yYXdpQkpNaVEI would be happy to add/update anything that improves this answer, so comment away.References:Floorplan of a volvo:http://www.volvobuses.com/SiteCollectionDocuments/VBC/Global%20-%20ILF/Downloads/8700_range_UK_051006.pdfKawasakis floor plan of the R143:http://www.kawasakirailcar.com/LRTR143.htm#US Road Statistics about materials used in roads:http://pubs.usgs.gov/fs/2006/3127/2006-3127.pdfTesla S official Blog about efficiency:http://www.teslamotors.com/blog/model-s-efficiency-and-rangeSao Paolo Bus system:http://spectrum.ieee.org/green-tech/mass-transit/how-to-keep-18-million-people-moving/0Cross sections:infovisual.info

The good, the bad, and the ugly. I’m a fairly recent proud owner of my Model S P100D, but I do a lot city traffic driving, as well as some 2.5k miles + return journeys.TLDR Model S: Expensive to buy, extremely cheap to own, under warranty, at least so far (~12 months). Amazing to drive, somewhat poor quality car in terms of luxury compared to other cars in its price range. Software is amazing, autopilot above any other car.Should you buy a Model S/P100D? Yes if you’re after a toy, otherwise buy a Model 3 instead, or a fleet of them. P100D is for adult children with more adrenaline rush than sense(yours truly). High spec Teslas simply aren’t worth the money, unless you’re a very very confident driver and you want to win every traffic light drag race.If you still want one but don’t care about performance, buy cheap, even if you want more, benefit won’t scale, and you’ll still have a car faster than 98% of all other cars, sports cars included. 4.2 seconds in a Model 3 AWD is on par with a Mercedes AMG Sedan, a Bentley GT pre 2019, etc.Futuristic: The most amazing realisation when you own a Tesla is that electric will become standard. For now, it’s very expensive, because scaling up and doing R&D costs money.There are problems for sure, the charging network, the service industry, the speed of charge, the cost, and so on. But it’s so incredibly obvious electric cars are so vastly ahead as a mass market product, there’s simply no question where the world will be in 30 - 40 years. It won’t be long before petrol cars will be a very old memory, and something generations to come will only learn about from stories.A word of caution: This review is written by a man child with more love of fast cars than sense, the very audience for the P models. A lot of it applies to all the Tesla range, but it’s a review coming from someone after easy to own sustainable performance, not an economically sane family sedan, where I honestly think the Tesla would come off a lot better.Collection day photo of my pride and joy.GoodThe way it drivesIt really doesn’t feel like anything else you’ve ever set foot in. The power delivery and the AWD system is insane in the best of ways. This car knows no weather, and does not care much for road conditions either, you can floor it all the way whenever you feel like it. It’s perfectly stable at all times, and it feels incredibly safe, plus you can accelerate out of harms way whenever you need to.Is it a true sports car? No, absolutely not. It’s a big heavy family sedan, with Porsche 918 Spyder vibes only up to 70mph, not much going for it beyond that. But if you’re in a busy city it’s a dream, you have on tap the launch power of a £1m+ exclusive hyper car for run costs of a Toyota Prius.This is the essence of what’s insane about it, any other brand you go to you would need to drop very serious cash, multiples of a Tesla price, to get anywhere near the same drive train quality.Here’s my friend trying the P100D for the first time. The speedometer reads in miles, so that’s a 0 - ~105kmh. It feels like you’re in the Space Mountain in Disneyland every single time.If you skid in a Tesla, you’ll be the first, that’s how insane the power delivery/traction system is. It’s not fun in the controlled drifts way, it’s fun in the “holy craaaap” way.You get used to it after 1 - 2 months, but 0 - 60 in 2.28s seconds or whatever makes all other cars obsolete in city driving, and unlike sports cars, it doesn’t cost you a small monthly fortune to be naughty in a Tesla all the time. Quite literally, nothing, not even a Bugatti, can hold a candle to you in city traffic. Seriously: List of fastest production cars by acceleration - Wikipedia.When the worlds most expensive Ferrari or insert name here creeps up in front of you at the traffic light, it’s amusing and entertaining. Nobody can ever overtake you from a standstill, and there’s no such thing as an yellow light anymore, which come in quite handy if you can use them responsibly.That kind of launch power in a petrol car is a major event, it means launch control, good grip, no wheel-spin, good weather, dry road, even road surface etc. In a Tesla it’s business as usual, all day every day, every time you floor it you’re flying, you don’t even think about it, it feels like you’re playing an unrealistic PC car game. Driving a Lambo like car through the city at that speed of flow is impossible, any car with anywhere near the performance to 60mph would be too low(close to the ground) and too compromised to compete, you’d have to cause very serious damage to the car to keep up with the Tesla.“Really? Tesla vs Lambo? Reality check please”. I’ll let you judge for yourself, courtesy of DragTimes, Model S P100D vs Aventador SV Launch Control. I’ve tried that competition in person, in my own SV. Without launch control, the SV has a very unimpressive throttle response, there’s almost 1.5 seconds of delay in between flooring it and it starting to move. The Tesla simply flies.Here’s a cuter sample, courtesy of a dear friend and his son.Run costs are near 0It’s not cheap to buy, but after that life gets a whole lot easier, unlike other cars(especially performance ones), which generally require a continuous forking of cash for things every month. Without oil to replace, break pads and discs to worry about, anti-freeze and a lot of the petrol engine saga, there’s almost never a reason to open up your wallet again.Mine was a fairly expensive, 6 figure price tag, high spec P100D. Ever since? £300 on a tire + replacement because of a nail, nada on all else, and still drove 2000km with a nail in the tire before it was found.I live near a supercharger which helps tremendously. Tires will wear out because of the acceleration, but they already behave much much better than other cars I’ve owned, and 4 tires every 2 years is something I’m happy with.Servicing is run on a 0 profit model.Maybe the most amazing and understated feature of being a Tesla customer is the way they don’t try to rip you off in a service.Owning other brands, at even higher price ranges, has meant a very off putting routine of every 3 weeks visiting lets say Mercedes Service, for this reason or the other, all at a very very heavy premium. They always take forever, cost a fortune, and don’t care for you one bit, except for selling you stupidly expensive monthly care packages that don’t actually end up covering for anything..If you call Mercedes, you go through 5 answering machines, and you have this back and forth test of patience with their absolutely idiotic phone system. It’s not possible to call your service technician directly, they never have a replacement car, and when they do it’s not even supplied by Mercedes, but a third party company, etc. If you want to get things done fast, they tell you to come at 8AM, you turn up and you’re casually told service technicians are not in until 11AM, things like that. The best or nothing as they say, so you truly get the nothing because it’s cheaper for them to make it happen.If Mercedes is the most incompetent car brand of all time at post sales, Tesla is the very best there ever was. If you call them from a known phone number in their system, by the time someone picks up the phone, they will know who you are and what care you’re on about.Mobile technicians are deployed, and there’s never a talk of cost estimates, because warranty means warranty in Tesla, and that’s pretty amazing. I had a door mirror replaced post a minor incident, no one ever talked about dollars.Government likes you buying EVs(at least in the UK)The purchase terms of an EV are very friendly, and the Tesla staff has been extremely useful in pointing out the correct channels.A £5k government contribution, no congestion charge(otherwise, £11.50 per day), no fuel no matter how you drive, and barely any consumables(no engine oil, no break pad/disc wear due to regenerative breaking etc). Business owners choosing to purchase EVs are allowed to do so pre-tax, unlike all other types of cars, with a significantly decreased tax burden for benefits in kind, which will go to an even lower 2% in 2020.Leases are very competitive, so the conversation starts at half the APR your average dealer would begin talking to you. With New Inventory, I have been offered an APR of <1%, which is a steal.There’s a lot of spaceThere’s more trunk and frunk space than in almost any other car, and short of buying a semi-truck, you won’t get more load capacity buying from the competition. This is pretty cool if you have a family to carry around.I generally carry everything I need to carry, which my one laptop bag, in the frunk, so it doesn’t wobble around as I drive through the city like I’m auditioning for a role with McLaren’s F1 team.It’s really convenient, and you do feel the car has great light permeability, the sunroof is really fun, and the really big windscreen is pretty cool, there are barely any blind spots when driving, and it’s a great feeling of openness.The autopilot is incredibleIf you’ve never trusted your car to drive itself before, it takes some getting used to, but you’ll never go back. If you’re tired, drowsy, on your way back from work on a late night, it’s perfect. I am comparing it to one of my other cars, a Mercedes with Distronic technology, which will casually steer into adjacent lanes, not keep pace etc. Cruise control/distronic are highly useful on a motorway, urban use is a problem, though Mercedes explicitly warn you against using Distronic in the city.The Tesla is pretty spot on at all times, and I’ve done 2000 miles plus in a single journey on autopilot, taking over only for roadwork areas, where lane markings are confusing, and I’ve done it at 95mph/150kph, the car can be trusted. Hands off the steering allowed only up to 20 seconds, so for now it’s not fully autonomous, more of a “party trick”.If you ignore the car’s warnings to put your hands back on the steering, auto-steering will become unavailable for the rest of your current journey.If you drive at 150kph in autopilot and press the acceleration, auto-steering is also automatically disabled, so the car will penalise you for trying to be too naughty.Confusing lane markings, such as new lanes on old road, roadworks, etc, will nearly always confuse it, so watch out.Below is a video of me doing 150kph with the Tesla autopilot, intentionally driving at the max speed possible, on a completely empty road and perfect weather conditions. Great scenery too.Most of the interior is pawned from MercedesThe indicators and many elements of the steering column are borrowed from Daimler, because they are exactly the same as in my S class and I’m sure other Mercs. If you’re used to a Merc, you can jump straight into a Tesla, and your reflexes work instantly.The best part is that there’s no on/off in a Tesla, no button to press. You simply put it in drive mode and off you go. At the end you press the P button at the end of your mode switch and done, no off button. That’s quite fun.BadThe car feels really cheapIn spite of its very generous price tag, the quality of everything you touch is on par with a car 1/4th of its price or less. Note, it’s a good looking car, and I don’t want to try and account for taste, but the interior looks like an entry level Ford or worse.Many people love the “minimalistic” approach, however they tend to be people who don’t have the experience of owning a Tesla or if they have a Tesla they’ve never owned another car of a similar price tag, so they cannot compare. Interior wise, it’s a 2.5 out 10 for the Tesla.It’s a little bit of an unfair comparison, as the price gap from a 75D to a P100D is mostly battery and tires, and they are not secretive about that in any way, but I still feel mass producing the interior could be done better, and in time I have no doubt it will. Over the years Tesla has always incrementally upgraded every detail about the car.This is about comparing a 6 figure priced car with other cars in a similar range.The consumption range is too dramatic. Being a wildfire traffic hopper can mean you have to charge every 2 days, up to 75%. It’s pretty incredible, but in Ludicrous+ the range calculator is another piece of decorative kit. The computer is simply pretty useless at adapting to individual driving habits, location, or recent consumption, instead of re-working your averages, it provides you with a false rolling instant value.E.g you’ve done 800Wh/mile until now, we’re still going to assume you are going to do 250Wh/mile until destination. That means in city traffic and power driving, you could get as little as 120 miles of range in total and Mr computer is largely useless at warning you in advance.The paintwork sucks, it’s really really crappy, and it gets dirty all the time, and it just looks cheap. It also costs £1000, which is insane, because it’s 100% not worth it. A paint job in a base spec Mercedes is another world apart quality wise. Same story for the rims and wheels, cheap stuff with cheap paint over it, sold in a very expensive wheel upgrade package.The car has out of the box LTE internet/connection, but it’s really poor, and as soon as you’re out of the home country, good luck. The number of times the GPS crapped out, or Spotify stopped working, too many to count, so it’s a completely unreliable connection. You can pay and add your own SIM card in the car, which improves life a lot.The steering wheel is way way too big and uncomfortable and nowhere nimble enough, that whole steering column could do with a massive upgrade. It makes it tiring for long drives, and manoeuvrability is terrible, the turning radius is only slightly smaller than the circumference of the Earth.The headlights are too powerful, to the point where other motorway users constantly flash you to warn you you’re on full beam, even when you’re really not.The car feels like its made of cardboard entirely, and the door feels like it weighs 500 grams, but not in a good way. No soft close, no nicety features, leather is very poor quality, no massage seats, no seat cooling, no proper seat settings(lumbar support etc).Cry me a river I know, but these are all common features in other cars of similar price. When you slam the door to close it, which you have to, it feels like you’re about to tear it in half. Other cars in this price range will always have soft close.The lights inside the car, both interior and the trunk/frunk are useless. I don’t know how they managed to cheap out on these, but it’s painfully annoying, dinner candles in the 15th century were much more powerful. There’s also no 12V socket in the trunk or frunk(seriously???).It’s completely missing on the nicety features you’d expect, like a decent set of air vents. Everything is cheap cheap cheap, and doesn’t really work at all in very hot weather, where you have to drive with the ol’ windows open technique.The cupholder system is a nightmare, and the storage space is pretty useless for a car of its acceleration. There’s nowhere to put stuff to prevent it from flying all over when you floor it, it’s very poorly thought through as a performance vehicle. If you don’t drive like you’re trying to beat Ayrton Senna theres plenty of space.The sound system is decent but could be better too, in spite of the Dolby Digital surround sound etc, it’s not on par even with the entry level sound systems in cars of similar price(S Class Coupe, Range Rover Autobiography, Aston Martins, Bentleys etc etc).The performance is inconsistent, after you floor it a few times and accelerate all the way to motorway speeds, the car will cut you back significantly to prevent battery overheating. This happens very very quickly. In a petrol car, I can be wild all day long on a track, in a Tesla I’d be out of juice in one lap.The front windscreen is great for visibility, not so great for direct sunlight. Fortunately not often a problem in the UK. You get massive sun glares or condensation from battery heat all the time. I don’t know how you make something this bad, a 20 year old Vauxhall(Opel) Astra does better.It’s physically very hard to see in front of you on a sunny day, and it’s a basic thing in any other car. Not in a Tesla.The windscreen wipers are extremely feeble, and consequentially when you drive at speed/wind, they look like they are about to fly off, and barely work. They are too thin and cheap, especially for the massive windscreen they have to deal with.The GPS is completely useless through a busy city, it has no knowledge of traffic whatsoever, constantly takes you down poor routes, and so on. It’s a decorative piece unless you’re driving long range.Top end Teslas are not as fun for petrolheadsHaving a Tesla is quite fun for the engineer inside you, and for the futuristic geek inside all of us, but the inner child is left with a bitter taste of disappointment. If you’re a real car fanatic/adrenaline junkie, you might want to skip buying a Tesla, for now, because it’s dtill a heavy sedan with a big turning radius, so not the thing you would take to the track. Kills at the drag strip though.The straight line speed is fun for the first month, but the truth is 6 figures on a car will never ever make any financial sense, unless you’re buying a big semi-truck and your name is DHL.It’s a straight up vanity purchase, no two ways about it, especially in the higher echelons of Tesla pricing, but it’s missing any kind of excitement whatsoever. Not really the biggest problem in the world, but if you buy a toy for the entertainment value and smiles per electrons, Tesla is probably not your top choice. It’s absolutely incredible for the city though, probably one of the best daily drivers out there, for any amount of money.The interior, the lack of sound, the poor interior lightning, and the various details remove the sense of occasion and excitement, no matter which model you buy. Other cars for the same money would either give you serene luxury you would enjoy every time(S Class, Audi A8, Porsche Panamera etc), or full on boy racer noise and performance, as well as great luxury(Mercedes C63S/E63S/S63 Coupe). It’s also dangerously close to the price of a barely used Lambo Huracan, McLaren 570S or a Ferrari 458, which are extremely fun cars to own.With a Lambo/McLaren/F Car, you know you spent the money at all times, and at all speeds, it just feels amazing and even going to the supermarket is an occasion, in a Tesla it’s too civilised, which makes buying a top end Tesla even more unjustifiable, since you don’t really need drag strip record times for the city.Longer journey? Double up the timeLonger journeys take much longer, anything above 500 miles requires serious planning&math. If you’re a statistics nut like I am(life of the party I know), it’s pretty cool, and a bit scary.The consumption in a Tesla increases far more than in a petrol car depending on your driving. I’m comparing a P100D with the average performance petrol car, which is why the mpg figures are quite low versus the average car.Motorway cruising at 70mph, ideal weather conditions.Tesla: 200 - 240Wh/kmSports Car: 20mpg - 22mpg or 14L/100km.Motorway cruising at 100mph(Autobahn in Germany, ideal weather conditions.Tesla: 400 - 450Wh/kmSports Car: 16mpg - 17mpg or 17L/100km.If you’re doing that kind of long range you want to keep a good speed, but you simply can’t or you’ll miss your next charge. In a Tesla, you are constantly calculating and optimising. Do I drive faster because the battery charges faster in the initial phase, so it’s fine to end up at destination with less charge? Do I keep pace? Have I accounted for wind? Why am I doing 300Wh/km at the same speed as I was doing 250Wh/km earlier? Oh, 1% elevation, hmm. All part of the fun.Like in no other car, you get to feel first hand how changes in weather conditions, elevation/incline, road surface changes, affect “fuel economy”, because Tesla is kind enough to give you a live rolling chart.As a rule of thumb, you will lose 40 - 50% of the excess miles. E.g if your next supercharger is 200 miles away, I would charge for 300 miles, and hope to have 50 - 60 miles of range left at destination. Even at constant speed, the GPS estimates are way off. You will always arrive earlier than predicted, with less range left, even if you autopilot at constant speed all the way there.Realistically you will need to stop every 250 - 300 miles, and spend 40 min - 1 hour each time.Supercharger coverage is still a problem, for nowIt’s absolutely amazing that you can drive so far and for free, but it’s not something you can take for granted just yet. For one, the European coverage for Tesla is pretty scarce. You can get from A to B for most of it, but not efficiently.It looks good on a map but compared to petrol stations it’s nothing, for now. You incur a significant number miles added to your journey, just so you can pass through superchargers. On a 700 mile journey in a petrol car, you might do 1000+ in a Tesla, not even accounting for the charge time. If you’re in France/Italy, you will pay additionally for every charge, as you’ll go in and out of the same motorway to access the chargers. It can be as much as 2 -3 times the toll charges in a normal car, if you do this very often it could be meaningful.Superchargers are rarely located in places normal gas pumps are, and have no service industry around them yet. That means you may or may not get a toilet at your next stop, which in long range mode can be fun. If you’re lucky, you end up near a shopping centre. This is in Orange, France. The GPS on the car will tell you what facilities await at your next stop, so you can in theory pick and choose, but in practice this can add huge mileage to your journey.Most Superchargers in France have turned out to be “in the middle of nowhere”, in the courtyard of some hotel etc etc. It’s a little bit weird stopping for an hour at 2AM in complete darkness in the middle of a field.Value for moneyLooking at the competition, say S Class, spending £75k for a base model is a whole other world from dropping £140k on an S63 AMG, or a used Maybach, completely different planet. Looking at a Maybach vs an S560 is a visible, obvious, world apart difference, no one would wonder where the £££ went.In a Tesla, it’s the same car with slightly more range and acceleration. I know this falls more in the “cry me a river” segment of the market, but equally, you expect something for your hard earned dollar or GBP, which Tesla somewhat fails to deliver on. They are very upfront about it, more money = more power and more battery, but it’s a whole lot of money “just for that”.The option list is both surprisingly short and expensive. A little more software/equipment, some autopilot fancy gear that’s not legal yet, and a bit more battery, for “just” twice the price of the base spec. As a normal sensible consumer, this is somewhat extreme.It’s certainly the cheapest “city focused Lamborghini” you can buy, but beyond that the pricing structure really makes no sense in terms of value for money, and I would probably struggle to justify spending the same again.The sensible thing is to buy a mid range Tesla and save half the price-tag, and still get everything except the acceleration. Not being able to floor it in a Lambo through the city isn’t exactly the mass market problem solving Elon had in mind, but ironically it’s kind of all you get in the P100D.Conclusion: You’re paying for a power train, battery tech, and technology. You won’t get a fancy car, if that’s what you’re after don’t spend that kind of money on a Tesla just yet. Go half the price and get a Lexus hybrid instead. The car is really amazing in one way, a little boring in another. Overall the best piece of commuting/city gear you could ever have, though P100 models are ultimately an expensive toy.Love of Tesla: Having “talked it down” so much, I do feel the need to re-enforce the insane capability of this car is very addictive. Even if you’re fortunate enough to have driven crazy cars, yes it would get more feel, but you would not have more acceleration and torque, and the lack of sound is replaced by the consistent “holy sh******t” launch power at every single traffic light.Update(after 12 months of owning it): The honeymoon phase is now long over. The performance is still there, the run cost is still brilliant, but Tesla as a company is sometimes showing some fairly ugly colours.Tires lasted quite well, got a comfortable few mm of thread depth left. If you knew how I drive, in Ludicrous Plus constantly, that’s an insanely impressive thing, nearly 20k miles later. Loss in traction is noticeable, and I’m certainly way more careful in the wet than I was on fresh tires. At some point the £1k replacement cost will be unavoidable, in the next few months.Range is a big lie. 10 - 15% lost to software updates, restricting max charges further and further. I haven’t seen a number starting with 300 since the day I took delivery of the car. As detailed further above, do not trust the range of the car.Charging speed has decreased massively. It used to be you would drive to the supercharger with 10% - 15% and it would bump straight up to around 114kw - 117kw pretty much straight away, and stay there till the battery was nearly 80% when you could go home. No longer, the car now only goes to 85, then slowly to 95 and so on. It may be a software update to preserve battery life, however you have less range and longer charges.No yellow cornering on the screen which lots of other people report, but it’s definitely a pain in the a**, it randomly resets itself, as you drive, or as you follow the sat nav, for no apparent reason. Music cut offs etc for about 30 seconds while the screen reboots for no apparent reason.Suspension isn’t proving very reliable. 1 year in and squeaks and creaks from everyone single corner possible. Car went to service and got cleaned by Tesla engineers under warranty, all back to normal now, no squeaks and creaks.HEPA filter had to be replaced after 14 months, around £186 inclusive of VAT from Tesla. Not terrible and done same day, however it’s a consumable and not under warranty.Software updates coming constantly have actually made the car a lot worse. Now it barely ever reads speed limits properly. While the AP is fully trustworthy, it won’t change speed limits, so you have to pay attention a lot more or you might get a speeding ticket and those lovely points on your license.Completely new design delivered around 5 months ago, and I hate it with a passion. They’ve made it more Model 3 like, but it’s absolutely stupid, various things on the touch screen overlap, as if it wasn’t hard enough already to touch things accurately while driving.The Dolby Digital surround system constantly gets deactivated as an option for no reason whatsoever, which drives me crazy, and nothing I do seems to affect that at all, I have to remember to re-enable it every time I get in the car, which is not great for an audiophile such as myself, the sound system is pretty terrible anyway even if you go for the high end option, at least compared with proper in car audio systems.Would I buy one again? The answer is absolutely not, I got carried away by very low interest and tax benefits, and Ludicrous acceleration, but the honest to god answer is that I simply don’t enjoy driving it at all, it’s far too basic, too plastic and too crappy for the enormous price tag. I don’t dislike the car, but similarly I never look forward to drive it, and all I keep thinking is I could’ve bought x y z make and model instead.It’s coming from a place where I am fortunate that run cost isn’t my number one concern, but it’s been the only reason why I kept it, it’s very hard to say no to driving around for an extremely small cost, again when considering the performance. Like I said above, buying it is pricey, after you pay close to nothing beyond insurance. However, for the buy price of the car, I personally want a lot more.Value retention, Luxury, exclusivity, convenience, and a feeling of being able to drive it endlessly, like an S class, where after 15 hours of driving you don’t get that “sticky” feel of having been in a car for that long, you feel quite good.None of this come with a Tesla, and 99% of Tesla owners are extremely fanatic, but the reality is the majority of them don’t come from a high vantage point, and it’s by far the most expensive car they ever bought. Yes it may be better than a Honda Accord, but for many times the price tag isn’t that implied?The worst Tesla experience so farAfter a bump traffic so light that not even the paintwork on the car is damaged, the steering felt really funny, so naturally I pulled over into a side road, and phoned my beloved highly competent Tesla assistance.They quite literally told me to f off, there’s no other way to put it nicely. They said it’s not their problem, that it wouldn’t be possible to tow it to a Tesla depot(even if I offered to pay for this separately), and that the car is no longer safe to drive. Insult to injury and acid pour on it in the span of a 10 second conversation.I had the extreme luck this happened 2 miles from home, where it was manageable, had it been 3AM in the middle of nowhere, the messiah of all car companies would’ve had me stranded useless in the middle of nowhere, no their problem of course, the nearly 150k they billed me for the car just a few months earlier had long been forgotten from memory.Thanks to good friends, I made my way back home, and the next day after insurance told me they are happy to help/cover the costs, but the car should go to a Tesla garage since no one else can repair a Tesla, low and behold, it was entirely possible to pay and have the car towed. What in the actual f*ck?A very nice Joe shoes up 3 hours later with a tow truck, and while on the phone with his boss/colleague, he politely asks me to dictate my credit card details so he could further dictate them on the phone. I thought he was joking, but no, he was dead serious. I told him no way josay, take cash or no deal. One cash machine trip later, the saga ends, the car is loaded on the tow truck and off it goes. Or so I thought.The wonderful people at Tesla politely informed a new steering rack is required, post my 2mph barely any paintwork damage hit, for the great price of nearly £4000 inclusive of VAT. How wonderful, the steering rack mechanism can be completely destroyed by softly blowing air towards it, the build quality is insanely poor, more so than any other car I have ever owned, including a 20 year Vauxhall Astra I drove for a long time, with 200k miles on it and no problems.The truth? I’m seriously hoping this was a bad assistant on the other end of the phone, because this has felt like a slap in the face, which after the latest massive price drop adds a little bit of insult to injury. I’ve got a car worth a lot less than what I anticipated it would be worth, and a service quality that seems to fluctuate a lot based on who you get on the phone.

This answer refers to a prior version of the question.Famous joke: There are liars, damn liars and then there are statisticians!What it means is that one can "really" abuse statistics to show what they want to show without really understanding the true rationale behind it well enough. You really ought to understand the "essence" of things before using them. Here's my attempt at helping you with that. No charge ;)Mean: Most commonly it's the "arithmetic mean" (AM) that we tend to talk about. (Yes, there are others e.g. Geometric mean, Harmonic mean. Have a look at this question to know more: Which "mean" to use and when?)So what exactly is this mean (AM) mean? A mean (or average) gives you a single point summary of your data set. If you take your graph, the average/mean will give you the "center point" of the "distribution". Imagine you were to balance this graph on a needle tip so that it'd be level. Where should you place the needle tip? Hint: AMNow, the mean by itself is fairly a useless quantity (if you know a little statistics you'll know why).Example:Grade score of 5 students from two classes A and B:Class A: 20, 30, 50, 70, 80Mean: 50Class B: 48, 49, 50, 51, 52Mean: 50Same mean, but radically different performances on the exam! Same "center point" but no idea about how spread out the distribution of scores are! You really want to know that information since it can be very helpful.Sometimes just giving the range is also helpful:Class A: Mean: 50, Min:20, Max:80Class B: Mean: 50, Min:48, Max 52But it's possible to have scores like this too:Class C: 20, 49, 50, 51, 80. Same mean of 50 but mostly clustered around 50 with some values to the extremes. So the range by itself is not enough.Dispersion:What you want is a way to say "how much each point is away from the center/mean/average" and a metric to condense that information into a single number. Since distances are positive you don't want negative numbers - else everything would just cancel out. So I'll just use square of the distances instead and sum 'em up and take the square root to get me a good metric. Sounds OK? Good. (Why take the square root? Think about it, but I'll tell you later :)What you've now done is come up with a way to quantify the dispersion in the data set in a meaningful way. Thus, you want to know the variance in the data set (Read: Understanding "variance" intuitively) and you wish there was a single number to tell you that, like the mean is. You use the following formula (don't be intimidated):Conceptually, you subtract the mean from each of the values, square 'em up and take their "average". That's the variance. But then you get your units squared. Which makes no sense (e.g. [math]grade^2[/math]!). So you take the square root to get your units back. You call this standard deviation and represent it with [math]\sigma[/math] or just SD at times.Now, I present you with the following information:Class A: Mean 50, SD: 25.46Class B: Mean 50, SD: 1.58Class C: Mean 50, SD: 21.22Interesting. I now have a better idea of how everything is "dispersed" around the mean. I still have something missing? I may falsely imagine my distribution of points to be evenly split around the mean. Something like that:This is not always true. As you can see from the graph you've posted. You need something else too: A way to say "how" the distribution is shaped i.e., a number to tell you where the peak lies or how many peaks in the data set and is the data set skewed one way or the other and by how much?The "peakedness" is calculated by computing the Kurtosis and the skewness by computing well the Skewness (sorry, that's the term :)Once you have these numbers along with the mean you'll have a much better summary of the data.Your data set:So, for your data set (it's an image so I can't really compute anything) you could present it as follows:Overall summary: 1890 - 2010- Mean: xx- SD: yy- (really think if you "need" to show kurtosis/skew. What value do they add? Can you just show the graph instead?)First 100 years: 1890 - 1990- Mean: zz- SD: nnLast 20 years: 1990 - 2010- Mean: pp- SD: mmWas the change in means "significant"? Now, that child is a tricky question. What does significance mean? Does it mean the same thing to you as it does to me?Well that's where statisticians come in: They give you a rigorous definition of "significance" with respect to underlying math and the corresponding assumptions of the shape and distribution of the data set. The "test of significance" is then done and you get answers like:"The change in means is significant with a 99 % confidence level with a p-value of 0.05"Whatever the f*** that means!There are multiple "tests of significance" each with their own rules/assumptions. In your case it seems a Student's t-test would suffice to give you an answer like the one above. These are "statistical significance tests" and not "emotional/intellectual/interpretational" significances!! Be wary of such claims and be honest to yourself and the people you publish these claims to and prevent them from misconstruing the word "significant".So yes, in your case, it seems, that means/SD should get you a long way. If you want a statistical significant test, use something like a t-test to give you the answer: It compares two means from the same data source and tells you if the difference in them is really significant (But in which direction?) Aah! Now that is a clever question I'll leave you with for now :PFancy stuff:You could try to fit a "line" that best describes the flow of the distribution. But where do we draw that line? Think "mean" again here but you want to minimize the average distance between a point and the line. That's regression analysis for you. And will tell you what's the best line to explain the prediction of your graph.You still won't get a "trending mean" as you want. Maybe breaking up your averages and doing a t-test could take you a long way, IMHO than a full blown regression. If you don't know what you're doing, first see how much mileage you can get by going the simple route. Use regression to find out the impact of X on Y and not for computing any kind of average. Prior to doing that impact analysis, plot a scatter plot of X and Y and see if there is indeed any correlation between the two that you'd like to explore further. Only then go for regression. But you really really need to understand these things further since correlation doesn't imply causation (Does correlation imply causation? ). You can then move on to Time series Analysis to get to the guts of what' you're trying to tackle. But for the love of God, don't use statistical packages/Excel to come up with numbers without really understand the what/why/how behind them :)My suggestion: Go simple. Advance when you advance your own understanding of what you want to know and then go from there. Also: read this to reify your knowledge: Amazon.com: The Cartoon Guide to Statistics (9780062731029): Larry Gonick, Woollcott Smith: BooksHope this helps!