Hyundai may be inflating MPG figures - UPDATE: busted by EPA

[Ladogaboy]

As I understand it, the EPA does an independent, third-party estimate of each car's mileage. If there is a major, consistent discrepancy between EPA estimates and actual end-user experience, then the problem lies in the differences between testing and real-world scenarios. While there is probably no conspiracy on the fuelly website, I think it is equally unlikely that there is a conspiracy with the EPA's testing.

More than likely, Hondas respond poorly to the EPAs testing but better in the hands of average drivers, while Hyundais do well in the EPA's testing but poorly in the hands of real drivers.

I'd also be curious to see the demographic breakdown of the people who are reporting. It's very possible that people who bought Hyundais instead of Hondas saved enough money in the initial purchase that they aren't as concerned with getting great mileage/paying less for gas. It's also possible that older people are more likely to be able to afford the "better brand," and as a result you have older (and consequently more subdued) drivers in the Hondas.

But in the end, there are just too many factors to take into account. Let the EPA do their jobs, and if they've gotten it wrong, they should check the reasons why. This isn't the same as GM advertising the Cruze at 45 mpg before the EPA even had a chance to rate it.

[gone-ot]

...for the curious, here's what GM "...sent to..." EPA for the 2012 Model Year Cruzes and Sonics:

http://www.epa.gov/otaq/datafiles/FO...1_APPIPT1_.PDF

[BHarvey]

Got 44.7 on a 63 mile highway trip today, about 10 of which was in town.
But, of course, I JUST filled up with 90 octane E-ZERO!

And yes, I took a beaker with me and tested it BEFORE filling the car!

[Clev]

Originally Posted by Ladogaboy

Yet the Prius is getting worse mileage.

Maybe they're the same Prius drivers who pass me doing 80 mph.

The EPA test is here:

Detailed Test Information

Click the "Highway" tab. You'll notice that the initial acceleration takes 29 seconds to get to 36 mph, and it only actually hits 60 mph twice during the entire test. The average is 48.3 mph.

Since the test is almost exactly the same for every car, I could see a manufacturer programming the computer to sense the pattern of driving and adjust factors appropriately to max out the test.

Or perhaps the Hyundai is more aggressive about upshifting, which increases its score on the gentle acceleration of the EPA test, and is also more aggressive about downshifting to make it more "sporty" for drivers.

[niky]

A lot of cars are programmed to spoof EPA and similar drive cycles. I've noticed that Chevrolets, in particular, have schizophrenic engine mapping to ensure that at part-throttle operation, they're making much less power than they could, simply so they can meet some emissions or economy target (makes for funny dyno charts, with a huge valley straight down the middle).

I wouldn't put it past Hyundai to use a similar sort of system on their drive-by-wire cars, I've seen Hyundai test-units do good-to-great economy numbers on my typical eco-minded drive, but when you add a bit of zing to the drive, overtaking, accelerating often, the numbers seem to drop badly, so in average use, they're not quite as good as the Hondas I've driven.

And a number of people have noted (there was an issue about this locally) that Hyundai cars are tuned on the edge, making them sensitive to octane. A Shell engineer from overseas also mentioned this to a friend a while back. Octane sensitivity will mean that when you get a bad batch of gas, power and economy suffer. Hondas seem perfectly happy with low octane, as revealed by a magazine article a while back that noted an Accord makes more power with lower octane gas!

And Honda is one of the few manufacturers that seems perfectly content to let their engines do their thing. No weird engine mapping or strange power-sapping fuel-saving strategies. This allows average users to get the acceleration they want with a little tickle of the throttle, whereas said drivers presented with an engine mapped specifically for fuel efficiency will have their foot deeper in on the throttle at all times out of frustration.

In the end, YMMV. In our country, people complain about the fuel economy of Hondas because our driving cycle is vastly different. Less high speed cruising (where Hondas seem to excel) and more bumper-to-bumper 5 mph crawls, where the extra ratios on Hyundai six-speed automatics help quite a bit. (though people still complain about their economy)

[tjts1]

Sorry. Nobody is buying the conspiracy theories.

[Clev]

Originally Posted by tjts1

Sorry. Nobody is buying the conspiracy theories.

Who are you talking to?

[Gone]

Originally Posted by tjts1

Sorry. Nobody is buying the conspiracy theories.

Facts are a hard reality.

83 2011 Elantra owners have filled up their cars 2095 times, have driven 618,714 miles, are averaging 30.7 mpg, thought they'd get something from 29/33/40, and apparently, based on the OP, are unhappy. (Hyundai Elantra MPG Reports | Fuelly)

A hard reality indeed.

[Frank Lee]

30.7 looks like it's between 29 and 40.

[tjts1]

Originally Posted by Gone

Facts are a hard reality.

83 2011 Elantra owners have filled up their cars 2095 times, have driven 618,714 miles, are averaging 30.7 mpg, thought they'd get something from 29/33/40, and apparently, based on the OP, are unhappy. (Hyundai Elantra MPG Reports | Fuelly)

A hard reality indeed.

Unhappy with their own driving habits and looking to blame somebody else. Quite the 'fact' you got there. I wouldn't hang my hat on it.