Posted on 09/22/2005 4:57:12 AM PDT by grundle
http://www.wfaa.com/sharedcontent/dws/wfaa/daybreak/consumernews/stories/wfaa050920_wz_crmpg.769b7aa2.html
Consumer Reports: Overstating gas mileage
07:22 AM CDT on Tuesday, September 20, 2005
Consumer Reports
When shopping for a new car, the gas mileage is a top priority these days. Automakers' mileage predictions are based on lab tests like the ones conducted by the Environmental Protection Agency.
Cars are strapped onto a machine called a dynamometer. It turns the front wheels while a computer directs the driver to speed up and slow down.
Consumer Reports just analyzed the fuel economy data of every vehicle it has tested in the last five years. CR's Kim Kleman says this analysis reveals the mileage for 90 percent of the vehicles is overstated.
"The EPA tests don't correspond to the way most of us drive," Kleman said. "Their tests represent driving on a 75-degree day on a road with no curves or no hills, which is ideal for maximizing fuel economy."
The EPA tests haven't changed in 30 years, so they don't take into account today's driving conditions. There's a lot more congestion, idling in traffic, and widespread use of air conditioning.
Consumer Reports runs its own fuel economy tests. The engineers say these tests—done outdoors—give a much more accurate assessment of the actual mileage you'll get from a car.
Consumer Reports' tests often turn up results that are substantially different from the EPA's—especially for stop-and-go city driving.
For instance the EPA says you'll get 22 miles per gallon with a Jeep Liberty diesel, but Consumer Reports found you'll get just half that—11 miles per gallon.
With a Chrysler 300 C, the EPA says you'll get 17 miles per gallon, but Consumer Reports' tests get only 10.
As for a Honda Odyssey minivan, the EPA gets 20 miles per gallon; Consumer Reports gets just 12.
The differences Consumer Reports turned up with hybrids in city driving are even greater. The EPA says the Honda Civic hybrid gets 48 miles per gallon; Consumer Reports measured just 26.
"Newer cars tend to overstate the mileage more than older ones," Kleman said, "so the discrepancy between what you're promised and what you're getting seems to be growing."
Consumer Reports says with skyrocketing gas prices, that's a trend that's more troubling than ever.
Given the upfront cost differential between a hybrid and a gasoline powered auto, that difference could easily eliminate any financial advantage to owning a hybrid.
The last 3 or 4 cars I've owned have achieved mileage remarkably close to the EPA figures. And I don't feather the throttle. Perhaps Consumer Reports is doing it wrong.
interesting in that, by statute, cars are required to meet certain fuel efficiency standards - I assume as measured by the EPA. Could these cars be engineered to "ace the test," but not really engineered very well to save gas in real-life situations?
I have never gotten as good a number as they predicted but usually it has been close. Not so with my 2003 Saturn L-200 though. The estimate was for 23 mpg in the city and during the summer, with the AC on all the time, I am getting barely 16! :(
Same here - at the most it's been only 1 or 2 mpg off, which can easily be explained by variations in driving, terrain, wind, etc. They've all been real small cars, though (Integra, Toyota Matrix) - wonder if the difference increases with less fuel efficient ones, which require more care to get good mileage with?
LQ
I always thought that the mileage figures were given for comparison purposes only, and didn't reflect actual mileage a buyer was likely to get. "Your mileage may vary" means your mileage WILL be lower.
I would like to see ACTUAL mileage figures, but that varies widely based on driving styles by individuals, so it may be difficult to come by.
In other words, the sky is blue.
EPA figures are a "benchmark," not real world driving conditions.
Another thing I've found is that they more closely matched the EPA figures after engine break in. The Matrix got bad mileage when it was new (23 or 24, which for that car is bad) and it greatly increased once the engine had a few thousand miles on it, and I'm now routinely getting 31 or 32 during normal useage, and up to 36 on long trips.
I wonder how old the engines in the cars tested were.
LQ
Concur. Idling in the parking lot with the AC running is a rather poor way of calibrating MPG, despite the fact that many people do it. The EPA is giving you the mileage on the assumption that you are actually driving, not stuck in traffic. Not this may be the first time I've defended the EPA. Consumer reports has been drifting closer and closer into crackpot-land for some time.
If our money was not involved, it would be funny!
Considering that this comes from the leftists at Consumer Reports, I would expect them to say that the cars don't meet Bush's EPA mileage figures. No such problem existed under the previous administration, of course. (/sarcasm)
It doesn't matter what the numbers are, so long as all vehicles are tested under identical conditions.
Perhaps it would make them "happy" if all the EPA figures were reduced by, say, 20%? Works for me. In my particular experience, all the vehicles I've driven match quite closely the EPA figure minus 10-20%.
D'OH!
Quite to be expected when one leaves out driver variability and absence of wind conditions.
"Newer cars tend to overstate the mileage more than older ones," Kleman said, "so the discrepancy between what you're promised and what you're getting seems to be growing."
That is because automakers are no longer striving to build cars that get good milage, but are rather building cars that do well on the EPA test. The EPA test result is the figure used to determine Corporate Average Fuel Economy, so the auto companies need to get favorable numbers so they can sell more of the high-profit low milage cars.
The consumer is, of course, screwed. Not only do the auto companies produce vehicles incapable of performing their actual real-world functions efficiently, but they are also providing bad information. But the regulations forbid the manufacturers to use any figure but the EPA figure when advertising milage.
CAFE has been a disaster from start to finish. The definition of the exempt class of light trucks gave rise to the ridiculously inefficient and unstable SUV class. Now the definition of the test is giving rise to the new built-to-rule hybrid class, that does not come close to delivering what is promised.
If the whole rule were scrapped tomorrow, automakers would immediately start building the high milage automobiles that consumers demand, and consumers would insist that they actually perform as advertised. Overall fleet economy would go up almost immediately.
If the greenies were really interested in the environment, they would be campaigning against CAFE. Instead, they are more interested in control, so they are campaigning to make it even more obtuse and restrictive.
Just watching the instantaneous mileage info on the dash - the MPG number ranges from 2 to 200. Yes, the average does settle on some reasonable number, but it just reflects the particular mix of driving/terrain/ascents/decents/etc.
The best any published number can do is hold the conditions for that number steady and do the math. And then, just use the number for comparison with other manufacturers/cars.
Consumer Reports
"We Decide, You Listen"
Unfortunately their liberal enviro bias makes their decisions pretty lame.
20 yrs ago they had some credibility, at least on stuff like household appliances.
Now they seem to be wrong on just about everything.
"EPA figures are a "benchmark," not real world driving conditions."
I also thought it was quite amazing that my sister in law drives a VW bug and gets 29MPG on the highway and my Explorer Sport gets 27 MBG HWY. She gets the smiles and I get the finger. ?
Fortunately, there is yet nobody holding a gun to your head to buy one.
Last time I heard anyone seriously discuss "financial advantage" as a reason for a car purchase was in 1930.
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