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Tesla owner drives 452 miles on single charge
- hkmurakami 11y agoThe (imo, more interesting) stats in the video are missing from the article text body: Total Distance: 728.7km, 452.8mi Total Energy: 77.5kWh Average Energy: 106Wh/km, 171Wh/mi Driving Time: 18:40 hours Average Driving Speed: 39.0km/h, 24.2mph Total Stops: 1 hour Total Time: 19:40 hours Max Elevation: 94m, 310ft
- dublinben 11y ago24mph is an excruciatingly slow average speed for a 450 mile journey. No wonder they were able to be so efficient.
- 001sky 11y agoso, basically slower than a pro on a bicycle nice one
- jrockway 11y agoAlso a lot less energy efficient. They claim 171Wh per mile, that's 147 kcal per mile. On a recent 17 mile ride, I applied 591kJ (141 kcal) of work to the bicycle. So a bicycle ridden by a non-pro is almost 18x more energy-efficient than the car. (Of course more than 141 kcal of energy is required to get your muscles to do 141 kcal of work on the pedals. But not 2500 kcal worth, like the car would require. I wish a 1 hour bike ride burned 2500 calories.)
- asdfkajh2 11y agoOf course a bicycle that is what... 1.2x human weight... is more efficient than a car that is probably ~10x human weight, when you measure it by vehicle rather than kcal per mass.
- kennywinker 11y agoThe weight of a car is not optional. If I want to move some mass between point a and point b, and I do it by car, I have no choice but to haul along that extra ~10x my weight. Measuring by kcal/mass ignores this practical reality in favour of a more precise definition of "efficiency". Also if you're riding a bike that weights 1.2x your body weight, you have the wrong bike! Good god!
- dclowd9901 11y agoDon't know if you were kidding but I think the implication was the combined mass was 1.2x your weight. Of course even then, that's still a pretty heavy bike (I think my commuter clocks in at about 10% of my weight)
- dzhiurgis 11y agoNeither 4 passengers, pile of groceries, comfortable dry seats, infotainment & air conditioning are optional on bicycle. In other words apple to oranges comparison.
- darkr 11y agoA pro, or at least someone comfortable with averaging 25mph over a long distance; given a relatively flat course, would probably require an average power output in the region of 300 watts. So even if we take the higher speed into account this works out around 12Wh/mile. ..but if we take weight into the equation; assuming the rider and his bike are on the chubby side and work out a combined 100kg - we get 0.12Wh/kilo/mile. Most of the tesla range are over 2000kg excluding passengers, so taken as a Wh/kilo/mile calculation it actually works out around slightly more than 1/3 greater efficiency at 0.086Wh/kilo/mile. Not too bad..
- kwhitefoot 11y agoWhat would the pro's average speed be over the total distance? And what would an ordinary human being manage?
- devenson 11y agoIt required approximately 5.5 horsepower to propel the vehicle.
- Hermel 11y agoIt is obviously the speed that makes the difference. This guy only got about 110 miles (180 km) out of a fully charged 85 kWh Tesla, driving on the German Autobahn at 160 km/h: http://www.teslamotorsclub.com/showthread.php/32873-Discharging-at-High-Speed-(-100-mph) http://www.teslamotorsclub.com/showthread.php/32873-Discharg...
- gambiting 11y agoThe Tesla is poorly suited for Autobahn driving because it will actually overheat and slow down if you keep driving at 120mph(200km/h) for longer periods of time, and that's not really difficult on the autobahn, especially at night.
- tempestn 11y agoGiven those stats, his average power usage was 4.1kW, or about 5.5HP. Not bad considering that's input power including all peripherals and losses, not just power to the wheels.
- kwhitefoot 11y agoThis is about 20% less than the rule of thumb number for the power needed to keep a modern mid size car moving at about 100km per hour. I forget where I read it. So yes pretty good. And this is the principal reason why internal combustion engines are so inefficient in practice, they are used at a tiny fraction of their rated output for most of their working lives. Of course the comparison is not quite as favourable as it at first appears because we should really measure the input power not at the output of the battery but at the input of the battery charger (equivalent to measuring the fuel pumped into a petrol engine's tank). Still impressive even if the conversion efficiency of the charger and battery combined is only 50%.
- tempestn 11y agoCool, do you have a source for that rule of thumb? That's a new one for me. That's about 8HP to the wheels to keep it rolling at 100km/h right? So obviously more than that from the engine. Re: measuring at battery input rather than output, that's a good point. Would definitely be higher that 50% charging efficiency though. I would guess at least 80% - probably > 90% if you charge it slowly enough. (Haven't done any research on Tesla chargers or batteries specifically, but I did used to be a power electronics engineer. High charging efficiency is important both for cost and, perhaps as importantly, because a slight reduction in efficiency can mean a lot of extra heat that you have to deal with.)
- kwhitefoot 11y agoAlas i can't remember and a quick web search doesn't find anything I recognize. But I did find this that mentions 10hp at 50mph: http://energy.typepad.com/the-energy-blog/2010/02/energy-needed-by-a-vehicle-part-1.html http://energy.typepad.com/the-energy-blog/2010/02/energy-nee... And a few hotrodders discussing the question here: http://www.hotrodders.com/forum/how-much-hp-required-60mph-113660.html http://www.hotrodders.com/forum/how-much-hp-required-60mph-1... This on PhysicsForums: https://www.physicsforums.com/threads/power-and-tq-needed-to-keep-a-car-rooling-at-speed.222959/ https://www.physicsforums.com/threads/power-and-tq-needed-to... And finally a paper with real formulas and better explanations: http://wps.aw.com/wps/media/objects/877/898586/topics/topic02.pdf http://wps.aw.com/wps/media/objects/877/898586/topics/topic0... Looks like my 5kW wasn't too far off.
- feld 11y agoI commented in another similar post but it seems to be lost... My friend did 438 miles with his P85 by drafting behind a semi the entire trip. With the extra range (efficiency!) of the P85D I'm certain he could have hit 500, easy. I don't recall how many Wh/mile he was doing but it was crazy low. I'm not sure why he hasn't been contacted about his drive, but Tesla does have the data and he's asked a couple engineers to look up his car and confirm. :-)
- beachstartup 11y agoobvious tip: this works for gas cars too. if you're extremely low on gas and in the middle of nowhere, draft a semi ... very carefully. luckily they don't brake very fast. i did this more than a couple of times during college road trips when i was broke as a joke.
- reustle 11y agoSometimes on long motorcycle rides you can take a few minute break behind a semi. Especially on a bike with no windscreen, your arms get really tired of pulling you against 60~ mph wind for hours. Pull up close behind a semi and the wind will disappear. Keep alert, like you said though.
- oomkiller 11y agoIt might be better to just take a break at a rest stop. A friend of mine was on a long distance ride across the U.S. and was killed doing this.
- withdavidli 11y agoSorry about your friend. While will get you more mpg, it's not worth it. When the truck hits their brakes you want enough time to stop. Other dangers are them kicking up rocks that can easily crack your windshield, and blown out tires (one hit my sisters car and took out a chuck of her bumper).
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- michaelbuddy 11y agowhat the heck, 19 hours for what a 7-8 hour trip max? If it's not real world, then why give it a headline? A scooter can get 95 miles to a gallon of gas. To me that's amazing.
- ianstallings 11y agoBecause those poor saps that wrote the article pay their bills by the click.
- userbinator 11y agoAFAIK lithium-ion batteries wear out quickly with deep discharges, so I wonder how much range he'll get on his next charge (or alternatively, how much capacity he lost.)
- nkurz 11y agoI don't think this is the case. Lithium batteries are generally much better with deep discharge than lead acid. Trying to power a heavy load below a certain threshold voltage will quickly and permanently damage them, but generally there is a low discharge disconnect that kicks in before this point. I don't presume he'll notice any particular ill effect.
- quanticle 11y agoLike nkurz said, the battery management circuitry will usually disconnect the battery before it discharges enough to damage the electrolyte. Granted, this depends on the circuitry in question (i.e. your $0.05 battery controller chip from Shenzen may not do this), but I would hope that Tesla is actually investing in proper battery management circuitry.
- greglindahl 11y agoGiven that the car won't let you discharge below 20% margin, it probably isn't affected at all.
- Qualman 11y agoIs there something special he's done to get this much milage out of the car? It's only rated for about 300mi on a full charge, so I'm curious if it's just luck, or more?
- Implicated 11y ago> Average Driving Speed: 39.0km/h, 24.2mph
- tekni5 11y agoI'm guessing you didn't watch the video or read the article, they didn't do anything special, just drove super slow on a very straight road.
- toephu2 11y agoWhen I first saw the headline on techcrunch I thought they modified the car somehow to get that range. That would have been a lot more interesting than just some guy cruising at 25mph.
- jfoutz 11y agoThe hypermiler thing always seemed kind of dangerous. https://en.wikipedia.org/wiki/Energy-efficient_driving https://en.wikipedia.org/wiki/Energy-efficient_driving 59 mpg in a plain old accord is impressive though.
- kennywinker 11y agoIf you're hypermiling to save money, good on ya. If you're hypermiling to save the environment, I suspect you're fooling yourself. The extra gas burned by people rage-driving around you has got to easily outweigh your gains.
- Animats 11y agoRight, big deal. "Nyland and the charitable friend who drove with him had to cruise an excruciatingly slow 25 miles-per-hour at near zero elevation to pull off the feat." This is like those solar car events where people find some long, straight road and drive bicycle-like things with solar panels very slowly. With a good road and hard tires, it takes very little energy to go a long way, slowly.
- 07d046 11y agoThose solar cars aren't slow. > By 2005, several teams were handicapped by the South Australian speed limit of 110 km/h (68 mph), as well as the difficulties of support crews keeping up with 130 km/h (81 mph) race vehicles. It was generally agreed that the challenge of building a solar vehicle capable of crossing Australia at vehicular speeds had been met and exceeded. https://en.wikipedia.org/wiki/World_Solar_Challenge https://en.wikipedia.org/wiki/World_Solar_Challenge
- ctdonath 11y agoHaving persuaded my LEAF to a predicted 120 miles on a charge https://scontent-atl1-1.xx.fbcdn.net/hphotos-xfa1/v/t1.0-9/10501796_10152918555362379_9203658750328292002_n.jpg?oh=c8e165105e07a45733cd75983237b66c&oe=56730953 https://scontent-atl1-1.xx.fbcdn.net/hphotos-xfa1/v/t1.0-9/1... I can very much appreciate the accumulation of tricks, nuances, and talent needed to actually achieve such range. Kudos to them for actually driving that 450. I'm afraid the EV market is going to collapse shortly before it can really take hold and eventually dominate. (Georgia just ended its massive tax credit for EVs, and the dealers are bailing out of the EV market with plans to ship all the used lease-returned vehicles overseas.) Great vehicles on the cusp of seriously viable battery range.
- limaoscarjuliet 11y agoI read an article on hypermilers the other day. They indeed can push the MPG in high double digits (e.g. 70MPG in accord) but... the approach is not very practical: - Switch to neutral and roll as much as you can, - Drive only in optimal range, - Close the windows, - Do not run A/C or radio, - Do not run lights, - etc. Needless to say they annoy pretty much everybody on the street who is around them. So yes, good result, but not very practical.
- mdasen 11y agoWouldn't switching to neutral increase fuel usage? When you're in gear, the engine is kept moving by the momentum of the car. When you switch into neutral and break the connection between the movement of the car and the engine, the vehicle has to use fuel to keep the engine moving and not stall. Yes, resistance will cause you to slow down quicker in gear than in neutral, but during that time you should be using basically no fuel compared to using the same amount of fuel that your vehicle would be using while idling if you're in neutral. Basically, while you're coasting in gear, you're using the car's momentum to run the engine rather than fuel. When you switch to neutral, the car's momentum keeps the car moving forward, but the engine needs fuel to keep going. EDIT: Popular Mechanics has an article on it http://www.popularmechanics.com/cars/hybrid-electric/a5977/coasting-in-neutral-fuel-economy/ http://www.popularmechanics.com/cars/hybrid-electric/a5977/c...
- waitwhatt 11y agoNo. The Model S will break the car for regen purposes if you are in gear. So you will lose speed but get a tiny bit more energy added to the battery. It's better to just go into neutral because that whole process is inefficient.
- kalleboo 11y agoI haven't had the privilege of driving a Tesla, but I have driven a Volvo prototype electric car[0] and it had two modes. One "emulate a petrol car" mode where letting off the accelerator would simulate engine braking (via regen). Then it had a "highway mode" where letting off the accelerator would just coast as if it was in neutral. The highway mode meant you could avoid wasting your momentum on a highway due to slight foot movements in speed regulation. Do Tesla cars have something like this? [0] http://www.plugincars.com/volvo-c30-electric http://www.plugincars.com/volvo-c30-electric
- donkeyd 11y ago> his two-year-old Tesla Video is of a P85D, which was announced less than a year ago.