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

[Gone]

Originally Posted by Ladogaboy

Of the cars that are listed, the Hyundais do tend to be a bit "sportier," and I wouldn't be surprised if some of those low mileage numbers are caused by the owners' driving habits.

The cars listed in the chart were 2011 cars claiming to get 40 mpg (plus a few 2012 cars, plus a couple cars near 40 mpg) based on a Motor Trend article. Not sporty or economy based.

You'd think that people reporting their fueling data would be more inclined to drive with an 'eye' on the accelerator pedal. Thus, numbers at fuelly.com, for example, should actually be better then the total driving population mpg numbers.

[Ladogaboy]

Yet the Prius is getting worse mileage.

With most of the members of this forum getting >20% better than EPA estimated figures, I'm guessing that those drivers on fuelly.com aren't driving with enough of an "eye" for mileage.

Also, I agree that people who report on fuelly.com are interested in fuel economy, and they are the same people who would be drawn to fuel efficient cars (like the Hyundai line up). However, neither of those facts mean that those drivers are actually knowledgeable of hypermiling techniques.

And by "sporty," I was simply referring to the fact that the Hyundai have better performance numbers than their Toyota and Honda counterparts. Having an increased power-to-weight ratio often leads to more aggressive (and consequently less fuel efficient) driving.

[SoobieOut]

I know that my Honda Hybrid is a throttle by wire, so the computer actually modulates the throttle linkage.

I wonder how many on the list are throttle by wire? Could explain the Honda difference.

[jakobnev]

As impressed as i am about 69MPG in a Ferrari Enzo and 38MPG in a DeLorean i'm a bit skeptical of their stats :P

[F8L]

One must also consider the number of people with very short commutes who will never reach EPA numbers. There are many Prius owners who are stuck in the low 40s because their commute is under 5 miles. That short of a commute would put an Elantra in the 20s. There are just too many variables.

[Gone]

^^^ Would you expect Honda owners to have different, average 'variables' compared to Elantra and Prius owners? Probably not. So what explains that a few Hondas do consistently better than EPA numbers and a few Hyundai's do consistently worse?

[F8L]

Originally Posted by GoZoner

^^^ Would you expect Honda owners to have different, average 'variables' compared to Elantra and Prius owners? Probably not. So what explains that a few Hondas do consistently better than EPA numbers and a few Hyundai's do consistently worse?

That's just it. We don't know what the people on Fuelly are doing for their daily driving. Nor do we know if people are just on there entering BS data either too high or too low just to make their model of car look good or bad. It's like having a bunch of mommy bloggers entering BS information because they are being paid by a company.

[Gone]

Just look at the histograms and you can see that there are no systematic abuses of the MPG data. Unless you want to postulate that some conspiracy theorist (Honda, Hyundai) have hired all fuelly users for their vehicles and have crafted a realistic histogram at an elevated MPG level (or for Hyundai, at a reduced level).

Also, fuelly.com takes steps to reduce competition - for example, by never comparing or ranking vehicles directly. This is described in their website forum (as a FAQ response).

Yes, abuses can occur. But you'll need more evidence to discount this set of data.

[user removed]

I just looked at a 1999 Maxima on fuelly and it was supposed to be averaging over 30 MPG, so I looked at the stats. One entry has it getting 70 MPG, over 400 miles on just over 6 gallons, while another has it using 15 + gallons and no mileage is entered. That one is total crap. Not sure about the rest but if that is an example then it is useless. Most of the rest are close to 22-23 MPG while my last tank was 28 with my mild hypermiling techniques and local route knowledge. Give me a deserted road and no traffic lights and I could probably put along at 45-50 MPH and get close to 48-40.

Mine are usually very consistent, with winter temps costing some and extreme heat in summer costing some with AC use. The CBR was at low 80s this summer and now it is the low to mid 70s with the colder weather.

As the manufacturers learn to build more efficient vehicles, it will get harder to get high percentages over EPA in mileage, unless you average speeds as very low and your efforts to utilize all hypermiling techniques are dedicated. Lower average speed get you there with less total energy consumed and will always provide much higher mileage.

I have driven our Sorento locally and on the highway for short distances and I can match the EPA figures if I am fairly careful. To get to 35% over in the Maxima is easy, in the Sorento it would be impossible.

In the context of my experience, my Austin Healey Sprite got 32 MPG in 1969. The Maxima got close to the same in 1999 and the Sorento got close to the same in 2011.
The Sprite was 1 liter and about 1200 pounds. The Maxima is 3 liters and just under 3000 pounds. The Sorento is 3800 pounds and 2.4 liters. The Sprite was probably 40 HP and would not go over 84 MPH. The Maxima and Sorento are much faster both in acceleration and top speed. 52 years of progress.

regards
Mech

[Gone]

Originally Posted by Old Mechanic

I just looked at a 1999 Maxima on fuelly and it was supposed to be averaging over 30 MPG, so I looked at the stats. One entry has it getting 70 MPG, over 400 miles on just over 6 gallons, while another has it using 15 + gallons and no mileage is entered. That one is total crap. Not sure about the rest but if that is an example then it is useless. Most of the rest are close to 22-23 MPG while my last tank was 28 with my mild hypermiling techniques and local route knowledge. Give me a deserted road and no traffic lights and I could probably put along at 45-50 MPH and get close to 48-40.

The 1999 Nissan Maxima is averaging 23.6 MPG based on 13 drivers and 688 fuel ups. Two screwups that you noted are not going to change the numbers notably. The graph at 1999 Nissan Maxima MPG Reports | Fuelly looks normal -> no systematic bias.