Popular Mechanics Deals Another Blow to Chevy's 50-MPG Myth

· · 7 years ago

Popular Mechanics recently spent 3 days and 900 miles testing the Chevy Volt, recording data on its all-electric range and extended range fuel economy capabilities.

So did the Volt impress? As usual, that all depends on your expectations.

In three drive cycles, the Popular Mechanics team recorded electric ranges of 31, 35, and 33 miles. To some of us who got used to hearing and repeating the 40-mile estimate that GM has used for years, that might be a little disappointing. But it shouldn't be.

As most people familiar enough with EVs to pay attention to these kinds of reports knows, there's no such thing as a hard electric range number. Your results can and will vary significantly depending on how you drive a plug-in car. Last month, Chevy basically admitted as much, revising their "about 40 miles" claim to "between 25 and 50 miles." This admission of reality was refreshing, and a smart move for any company trying to avoid a backlash when drivers achieve only half the range they might have expected in extreme adverse conditions.

So in reality, Popular Mechanics's electric range findings shouldn't be all that jarring to anyone who would care enough to read them.

But what may come as a surprise to many, is the once again disappointingly-low gas mileage that the Volt seems to get when operating in extended-range, or "CS" mode. Early on GM was using an estimate of 50 mpg when discussing the fuel economy for the Volt once its battery is depleted and its engine has turned on. Over the last few years, however, GM's CS-mode mileage claims have come fewer and farther between, to the point where GM has said almost nothing concrete on the topic in the last year. But over the course of roughly 800 miles of extended-range driving, Popular Mechanics says it recorded averages of just 31.7 mpg in the city and 36 mpg on the highway.

Not That There's Anything Wrong With That

These numbers aren't too much higher than the 27 MPGs that AOL Autos reported two months ago—and yet somehow, they have yet to elicit the strident denials from GM officials that those reports were met with. As with Chevy's long-held claim that the electric motor in the Volt will be the sole source of power for the vehicle's wheels, it would appear that the company has again overreacted to a report that turned out to be mostly true. Sure, the 27-mpg number probably was a little lower than what most drivers can expect to get in CS mode, but it doesn't seem to have been as far off as GM's outrage at the time suggested.

Even though the Volt team has been pretty consistent in its use of the "your results may vary" disclaimer when discussing the vehicle while it was still in development, at this point it looks like Chevy should probably adjust its 50-mpg rhetoric in the same way it did the 40-mile range claim. It's still possible that 50 mpg really is a reasonable expectation for the Volt in some ideal conditions—but that's no reason to use it as widely as GM has over the course of the last few years.

We'll find out soon enough what the EPA numbers for CS mode actually end up being. Those figures could very well end up being smack in-between the disappointing independent calculations that we've heard so far and the 50 mpg Chevy has trumpeted in the past. (Hey, 40 mpg ain't so bad, right?)

But regardless of whether the EPA numbers end up being 32/36 or 40/45, GM seems to once again be stuck in the position of having to manage expectations that nobody ever forced it to set so high to begin with. The question isn't so much whether fuel economy in the low- to mid-30s is enough for a vehicle that shouldn't have to run on gas very often anyway—it's why GM would go to the trouble of making overly-optimistic claims about a car whose reality is pretty darn impressive on its own?


· Anonymous (not verified) · 7 years ago

My beat up 1990 Honda civic gets 32-38 mpg religiously. I don't drive easy on it either. It only costs me $800. When I was 16 my mother gave me a 1978 Honda civic that always did better than 30 mpg. I think the VW bug got in the 30mpg range.

But I really have to wonder where the electricity for the volt charge comes
from? Are the owners doing solar or wind power? Last time I checked my electric bill cost per kilowatt increases as I use more. What is the real cost of the volt?

My step fathers Prius lasted 10 years before the batteries failed and cost $10k to replace. I guess we will be buying lots of lithium from China for these new "green vehicles".

· Anonymous (not verified) · 7 years ago

I have a 2009 chevy malibu lt with a 4 cylinder and 4 speed auto. I am getting 34 - 38 mpg on the highway and about 23 - 26 mpg in the city with the a/c off according to the cars fuel computer. The a/c drops the fuel economy by 2 - 4 mpg. I would have expected the volt to get around 50 - 100 mpg. Chevy should not have put a normal car engine in the volt, they should have put a gas or diesel generator in it which would have been more efficient. If the car is not going to get at least 50 mpg then the volt is not worth buying.

· · 7 years ago

None of this shocks me. From where I'm sitting, the Volt really missed all of it's initial targets. What we're going to see has almost nothing in common with the initial conecept. It was going to be high-performance, low cost and high gas mileage. Oops. X3.

Except for the big miss on the cost (though the lease makes up for that in the short term) none of these big "relevations" are show stoppers. And if you (the general you) were paying attention - you already knew the targets couldn't be hit so there's little shock to be had here.

· · 7 years ago

I never cared for GM but I did have hopes the Volt would change that.

This sure makes Phil Colley's attempts to protect the mileage of the Volt in the post that first reported the 27 Mpg humorous. Why does GM continue to make PR mistakes like this.

The Volt is simple. If you drive less the 30 miles a day and charge at home you will not need fuel often. Yet you can drive far if needed with gas. Just go with that GM.

The price is still high to me and like most families we require two cars. The Volt just does not make sense for us. I rather keep my mini van around for trips with the family and get a Leaf (have a Prius now) for my drive to work. oh well...

· Steven (not verified) · 7 years ago

Has Popular Mechanics or anyone else done the same kind of rigorous testing for the LEAF? Any opinions about which estimates are likely to be the most reliable?

One test I'm going to perform before shelling out for my LEAF is driving 30 miles up a nearby mountain range with an elevation gain of 6500 feet. The regenerative braking on my Prius SEEMS to repair the reduced mileage on the trip down. The show-stopper for the LEAF will be whether it can make the round trip with a comfortable safety margin (for summer trips when the A/C will be going full blast).

My evaluation will probably not make Popular Mechanics. So watch for it here.

· · 7 years ago

Steven, I would bet the house it will make it without a problem. You really only have to make it up because you will definitely gain energy on the trip down. I bet under most conditions you arrive at the bottom of the mountain at better than 30% SOC. Does it get cold where you are? Because the worst punishment you can dish out would be full heat & defrosters in below freezing temperatures, that will test the worst-case range more than having on the A/C in the heat.

· Ernie (not verified) · 7 years ago

@Anonymous: Unless you can buy gas at $1 a gallon, it will never come close to being as cheap as what your power utility charges for the same amount of electricity. You can expect any car to use about 200-250 Watt/hours per mile, so go by that number.

· Ernie (not verified) · 7 years ago

To use a useful example for my above numbers:

36 miles (one gallon of gas in your car, just for argument's sake) would use about 9 Kwh, using my high number of 250 Wh per mile. Multiply that by your electric company's rates, then compare to your gas station's rates. $0.18 per Kwh gets me $1.62 for your car's gallon-of-gas equivalent.

My electric company charges $0.0878 per Kwh on their tier-2 level, which I qualify for due to our electric heating. That's $0.79 per gallon. We pay around $1.16 for a *litre* of gas.

· · 7 years ago

Ernie -

Thanks! Using your math... and the fact that my EV does get about 250 Wh per mile, I calculate my fuel cost to be (drum roll please...) zero! Yay for solar power!

· Anonymous (not verified) · 7 years ago

I remember GM once advertised that the VOLD can make 230 MPG! What a hoax.

· · 7 years ago

Steven, you can estimate the elevation cost to your battery:
6500 feet is ~ 2000 meters,
The car weights about 1800 kg with cargo and passengers,
and gravity is 9.8 m/s/s

So, picking up the car 2000 meters takes 9.8*1800*2000 joules.
There are 3.6*10^6 joules in a kwh, which works out to
9.8 kwh to go up the mountain, not including usual electrical travel costs in level driving.
Convenient arithmetic ;)

No incline driving of 30 miles one way might use up to 10 kwh max, for a total of ~ 20 kwh to the top.
I think the only way you could get into trouble is if you have multiple hairpin turns that you accelerate out of and brake into the next over and over.

· Alan (not verified) · 7 years ago

What Chevy can do now is .... reduce the size of the gas tank, and add a compressed hydrogen tank - have a dual source motor - something like BMW did with the 7!

With the current ICE situation and overall price - Chevy is going to have a hard time selling these cars!

· · 7 years ago

If you think it would be hard to sell an expensive car that uses a widely available and cheap fuel... I dare say it would be harder to sell a car that uses hydrogen. Or to put it another way... having H2 as the secondary fuel (instead of off-board electricity) means that the car would be driven on gasoline far more often.

· ra5928 (not verified) · 5 years ago

I have a video on YouTube. "Chevy Volt: 50 mile range". Don't know how Popular Mechanics ever got those low results from the Volt's battery. Must have been 10 degrees and they were hot rodding. Who knows. I have never gotten less than 37. I average 45 in summer.

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