Hyundai Retreats on Fuel Economy Claims!

33 is not far off from the revised 32 mpg combined the Elantra sedan has now. Hyundai, Kia admit exaggerated mileage claims, will compensate owners [UPDATE] has pics of the updated mileage values.

Also, one should not interpret EPA mileage ratings as what you will get. One can learn more about the tests at Car and Driver: The Truth About EPA City / Highway MPG Estimates | PriusChat.

 

My CTh is EPA rated around 42, and I have averaged 55 meter, 52 mpg calculated for the past 6 months.

Should I sue EPA for false advertising ? Or something ?

[/tongue in cheek]

 

Maybe it is best to determine what "Highway mpg" means. Does that mean a highway for a few miles around a city or open road Interstate driving? My high figure mpg numbers I got in the 2011 Elantra GLS autobox were on the Interstates running 65-75 mph steady day & night until that tank was almost empty. That is my definition of Highway mpg. My low figure mpg numbers were running around in big cities on stop & go roads as well as city highways. Multiple stops every hour, no cruise control, driving normal. I call that City driving.

In a gasser car like the Elantra is, there is a huge mpg difference driving on roads with multiple stops verses hitting the Interstates and driving for hours with no stops with approximately 10 mph variation in speed caused by hills or left lane cops holding up the flow.

Mike

 

... for my other car, Cash 4 Clunkers forced me into a 20 MPG car which meant I had to rule out a 19 MPG Sienna although Sienna is probably in fact better MPG vehicle. I only really get 17 MPG. Just saying system is messed up if you're going to start making legal/marketing decisions based off of it.

 

In my across the country travels I regularly get 23-28 mpg combined in 2012 Sienna's. That's driving them nice but not going below posted limits. Lower numbers for more city driving and higher numbers for more Interstate driving. I have yet to run thru a whole tank in a Sienna in just city driving.

Here is what is says on the Prius window sticker about EPA ratings:
Actual results will vary for many reasons, including driving conditions and how you drive and maintain your vehicle.

To me that means these quack sue happy lawyers have nothing to base their case on.

Mike

 

I'd like to offer some perspective:

There was a time when the Jetta TDI advocates were making snide remarks about how their ride is equal to or better than the NHW20 Prius. So I picked up the Fuel Economy, user data, plotted it and found:

• EPA rating is not 'fair' to Jetta TDI performance
• Jetta TDI performance is nice but at best, 41/48 ~= 85% of typical Prius performance
  • diesel fuel costs reduces it ($3.568/4.030) * 85% ~=75%

I did this analysis because hybrids and diesels are competing, unusual technologies. But Kia is neither hybrid nor diesel so I won't be doing a similar analysis.

If Kia advocates would like to do a similar analysis, the raw data is in Fuel Economy and fuelly.com. Load it into a spreadsheet and make similar plots. If I were curious, I might have the energy to gather and plot the data but frankly, I'm not that curious.

It sounds like their product testing team took some short-cuts and this led to inaccurate EPA rating. A shame not just because of the distrust it breeds with customers but worse, it can fool their own design teams into thinking "we've done enough." They turn off their computers and go home only to wake up and find their work held up to ridicule for something not of their making.

They have my sympathy but it was always unlikely my shadow would have ever visited their car lots. Their "blue-motion" hybrid was interesting but the first generation vehicles have not even met the NHW11 performance metrics. Something is not right in the "blue-motion" world and I don't see an obvious problem.

Bob Wilson

 

This incident reminded me of another long ago involving Hyundai: Hyundai Wins Approval of Horsepower Class Action Settlement - Bloomberg.

 

Thanks but I just checked Fuel Economy:

	Column 1	Column 2	Column 3
0	[th]MPG[th]vehicles[th]model year[tr][td]41.5 MPG[td]14[td]2012 Passat	auto[tr][td]51.4 MPG[td]19[td]2012 Prius	auto

Source:Fuel Economy

If Wayne had visited Korea the correction might have been much larger. But this seqways to another table:

	Column 1	Column 2	Column 3
0	[th]min - max MPG[th]vehicles[th]model year[tr][td]34 - 47 MPG[td]14[td]2012 Passat	auto[tr][td]44 - 64 MPG[td]19[td]2012 Prius	auto

Source:Fuel Economy

This suggests there may be some overlap in Passat TDI vs Prius performance but only four owners reported these values versus the average which tends to suppress the outliers. A chart of all values is the best way to see the distribution. But if we take out the four highest and lowest values for these small sample sets, we get an improved range table:

	Column 1	Column 2	Column 3
0	[th]min - max MPG[th]vehicles[th]model year[tr][td]37 - 45 MPG[td]14[td]2012 Passat	auto[tr][td]46 - 57 MPG[td]19[td]2012 Prius	auto

Source:Fuel Economy

This second table, suggests the Passat TDI, automatic, diesel has no credible overlap with the Prius. The Passat has a little more interior space, 118 ft{3} vs 116 ft{3}, with more passenger volume but smaller luggage space.

Bob Wilson

 

Interesting as we have another datapoint from Wayne using the NHW20 in one of the early, marathon drives:

The black dots are from the individual logs and Wayne's data point is 121 MPG at 24 mph. It looks like the older 2004-09 Prius beats the Passat TDI. Still these points provide useful information.

The 'outlier' ratio to the average can suggest what a 'Stig', a reference driver, might accomplish by using partial fractions:

121/47.5 (NHW20, 2004) ~= x/51.4​

x ~= 131 MPG :: projected 'Wayne drive'​

We can test this method by using the Passat metrics:

90 / 41.5 ~= 2.17 :: Wayne Passat effect​

121 / 47.5 ~= 2.55 :: Wayne NHW20 effect​

Bob Wilson

 

As I explained before, there are very specific lab tests that are designed to be reproduced 10 out of 10 times, and the same for all manufacturers.

It has nothing with you getting 30 or 100 mpg. It has to do with tested car not being able to reproduce results from the test that should be always the same and thus be used to compare different vehicles in reliable manner.

There are plenty of Prius drivers that can get 70 mpg but that does not mean that Prius should be rated at 70 mpg.

My old diesel Avensis could also make 70 mpg on road trips if careful.

 

I think you meant," . . . until Wayne runs one in a marathon." My, Bob Wilson, benchmarks run only long enough to see the vehicle has achieved a reproducible, non-changing value.

Since October 2005, I've found 15-20 minutes brings the transmission to a constant temperature, ready for benchmark runs. Then a pair of runs, opposite directions, same course, back-to-back in unchanging weather, is all it takes for 5-10 miles. A shorter distance can be used if a data recording, OBD instrument is used. A longer distance is used with the cabin display. So here are my tests on my wife's ZVW30:


But testing styles are often driven by the goals:

• Consumer information - EPA, the reason this Hyundai thread started
• Vehicle mechanical health - Bob Wilson, benchmarks to help confirm something is not right
• Single tank drives - the Japanese 1,000 mile/tank club, a test of self-discipline, men and women and their machines in situ
• John and Hellen Taylor / Wayne Gerdes drives - sometimes done for a fee and always the publicity

Bob Wilson

 

Mike your post is the reason why that disclaimer is there

you stated

which implies that you feel that driving below the posted MAXIMUM limit is what? illegal? "un neighborly?", unsafe?

well, none of that is true. and the law might be wrong for the area of the freeway you are driving, but its not your place to determine that

or should we base the EPA ratings on everyone doing 10 over the limit? but how would that work when the limit is different? after all, you might be considered a dawdler if you were on that 85 mph freeway outside Austin TX.

 

I didn't say or imply one word about illegal, unsafe, un neighborly or quote any laws. I don't understand your reply at all. I was only stating what I did in the Sienna and by saying I was not crawling along but driving it normal. I could care less how someone else drives as long as it doesn't impact me on the roads. If there is a slower vehicle I will pass when safe. If I am going too slow for someone behind me I will move over and even slow down as they pass to make it safer.

Mike

 

perhaps i have read too much into your statement about your driving when i felt your statement implied that driving under the maximum speed limit is somehow less desirable.

for you to not break the law and comply with your statement, you must drive the speed limit exactly.

 

Bob/F8L,

Here is the 2013 Passat TDI trip report from Wayne...

CleanMPG Forums - View Single Post - 2013 VW Passat TDI Pricing, Options and Specifications

 

Oh my, why do I have to explain nothing to you? I just said I didn't go slower than the limits. That means I did not drive way slow to make the mpg numbers high. Just normal cruising down the road driving nice style. Nothing special, nothing illegal, no attacks on anyone, just driving. I am done in this thread. What has happened to Prius Chat?

Mike