EV Range High Anxiety: Normal Driving May Cut Range In Half

Paul Niedermeyer
by Paul Niedermeyer

Would you set out for a drive with your low fuel light on, knowing there was no place to buy gas? That’s the painful reality many EV drivers are going to be faced with every morning after unplugging their fully-charged battery and heading out on the road. Most conventional cars have about 50 to 60 miles left after the gauge hits empty, plenty of time to find a gas station. But according to a Consumer Reports test of a Mitsubishi i-MIEV, the stated range of 100 miles with a full battery is more like 60 or 50 under typical conditions, if you consider using lights at night, indulging in heat or A/C, or driving at 65 mph typical. I do. And so will most drivers. Disappointment with their $40k electric mini-car is inevitable. Just don’t say Darryl Siry or I didn’t warn you:

I wrote about the potentially misleading and confusing issue of EV range here, and former Tesla exec Darryl Siry has gone public with his concerns of EV makers’ unrealistic claims here, and more specifically, he took Nissan’s 100 mile claim for the Leaf to task here. The problem is well understood by EVers, but not at all so well by the public. Here’s the sixty second capsule version explanation:

IC engines operate at very low efficiency levels, from effectively zero% at a stop light, to maybe in the teens or low twenties at high speeds. We’re used to getting better mileage (range) on the freeway than in the city. But the amount of actual energy required to propel the car is much higher at speed; this is masked by the improved efficiency of the gas engine at those higher speeds.

An electric motor operates at close to 90% efficiency pretty much all the time, so there is essentially a direct correlation to the energy required to move the car, and the mileage (range). And since EV’s use no energy at a standstill (if the heat, lights and radio are off, as in the tests), city driving patterns are dramatically more favorable to EVs.

That explains why EV makers like Nissan and Mitsubishi are using the EPA City”, or “UDDS” driving cycle. This test cycle assumes an average driving speed of 19.59 mph and in the 22 minute driving cycle, it assumes you only break 40 mph once, for about 100 seconds, and never exceed about 58 mph. Not exactly a typical commute from the ‘burbs.

If the EV manufacturers used the US06 driving cycle, which more closely resembles typical US driving patterns, the projected range would be significantly less. But that wouldn’t look good in all the PR and ads. We’ve said it before and we’ll say it again: EVs potentially make great city cars. But head out on the highway, and you’ll be looking for an adventure all too soon.

Paul Niedermeyer
Paul Niedermeyer

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  • Guyincognito Guyincognito on Dec 18, 2009

    I'm a firm believer (despite my often skepticism) that EV's are the cars of the future. However, they are nowhere near ready (or needed) now. I always hear the average commute is 40 miles stat bandied about, and I'll accept that as fact. However, I would venture to guess that most people need to get groceries and pick up the kids from school a couple of times a week, nevermind regularly taking the kids to sports practice or going out to dinner, etc. A 70 mile range would not be feasible for such people. Will they exist as a niche vehicle for those rich enough to afford an impractical but likely not very fun second car? Sure. But we'll need another breakthrough before they are adopted on a wide scale.

    • Daanii2 Daanii2 on Dec 18, 2009

      I agree that electric vehicles are the way of the future. But also that they will have to be different from what we have now, or what the current carmakers will put out in the next five years. I think a serial hybrid electric car can be made that gets 0 to 100 miles per hour in 10 seconds, that burns diesel to generate electricity and gets 100 miles to the gallon. That kind of car will work much better as a drop-in replacement for our current gasoline cars.

  • Seabrjim Seabrjim on Dec 18, 2009

    Well put, Robert.

  • Michael S6 Took my car for oil change on Friday and dealership was working on paper. Recently one of the major health care system in our area was hacked and they had to use paper backup for three weeks. What a nightmare.
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  • 3-On-The-Tree I don’t think Toyotas going down.
  • ToolGuy Random thoughts (bulleted list because it should work on this page):• Carlos Tavares is a very smart individual.• I get the sense that the western hemisphere portion of Stellantis was even more messed up than he originally believed (I have no data), which is why the plan (old plan, original plan) has taken longer than expected (longer than I expected).• All the OEMs who have taken a serious look at what is happening with EVs in China have had to take a step back and reassess (oversimplification: they were thinking mostly business-as-usual with some tweaks here and there, and now realize they have bigger issues, much bigger, really big).• You (dear TTAC reader) aren't ready to hear this yet, but the EV thing is a tsunami (the thing has already done the thing, just hasn't reached you yet). I hesitate to even tell you, but it is the truth.