TDI EPA figures off?

[bates]

Has any one else noticed that the EPA fuel economy figures for the VW TDI seem to have been lowered well below the actual mileage?

I was looking at the possiblility of trying to take advantage of the Cash for Clunkers and trade in my Acura Integra for a TDI Jetta only to find that the TDI's average MPG is rated at 33 MPG, which is less than 10 MPG better than my Acura's 26 MPG. I know from this site that many TDI owners are averging 50 MPG or better with their TDI's.

It appears as though the EPA is intentionally manipulating the numbers to put some vehicles and manufacturers at a disadvantage while others are given grossly optimistic figures. My wife's minivan claims 26 MPG on the highway according to the EPA figures, yet I have never hit 25 and I regularly exceed 5 MPG over the highway numbers for my Acura so my driving style is the same it is the EPA numbers that are varying.

Similarly, the CARB (California Air Resources Board) will not provide the single occupant HOV lane stickers to the VW TDI nor the Mini, both of which provide signifcantly better highway mileage than several of the other vehicles which have rights to the coveted decals. It appears as though the stickers are given to manufacturers based upon "Political Contributions" rather than actual MPG and fuel economy data.

I would have liked to take advantage of the Cash for Clunkers program, but alas it appears as though the politicians in Washington are going to punish those of us who bought fuel efficient vehicles of our own free will prior to the programs start date. If they really wanted to encourage people to buy fuel efficient vehicles then they would have given the $4,500 to anyone who buys a vehicle whose average mileage figures were above 30 MPG, regardless of what was or wasn't being traded in. Or if it was intended to stimulate the economy, then make it for US manufactured vehicles only, keep that money here in the US. Sorry for the rant, it is just my $0.02, and I'm irritated that the program clearly is politically motivated rather than environmentally motivated as it is being promoted as.

[mathowie]

This post probably came out sounding more like a rant than you intended, but it appears to me as a complete outsider that you are looking for reasons to blame organizations with some pretty wild ulterior motives that I don't think are true.

The EPA figures used to overestimate fuel economy. My wife has had a Jetta TDI since 2002 and we only approached the upper estimates on long road trips where it was 100% freeway driving. They've adjusted downwards and reflect more of what we get in normal driving.

Our TDI figures are skewed due to the high population of TDIclub owners that have migrated here from the VW forums. Like most forums, this is a group of highly motivated people that share a common interest and a way to get noticed in a group like that is to attain a very high MPG figure. I've heard of people in the group that have done a no-A/C, 50mph drive across several states in an attempt to get 60+ MPG using a diesel Jetta. They're not a typical population of Jetta drivers but skewed upwards where 50 or more MPG is standard while me with a scan gauge in my wife's car I can barely top 40MPG.

The CARB rules are based on hybrid engines, plain and simple, and yeah that's unfair when mild hybrids that only get 22MPG are allowed in the lane but the rule was put in place to encourage manufacturers to make more hybrids and buyers to buy more hybrids and it wasn't strictly a high-MPG rule though I'm sure that was the hope in passing it.

It sounds like you could take advantage of the Cash for Clunkers program but you would get a reduced amount like $3,500 instead of $4,500. Is that thousand dollars really preventing you from getting a new car?

I don't think any decision or rule here is due to political contributions or purposeful skewing of data to disadvantage any car makers.

[jhu]

There seem to be a lot of hypermilers in the TDI crowd on this site, but the average TDI owner is not and is likely getting close to the EPA numbers.

[bowtieguy]

i could play the devil's advocate for both of you(Mat and Bates)...

you have to remember that the EPA estimates are based on COMBINED highway/city driving. can those estimates be bettered? ABSOLUTELY! and what type of driving are the 50mpg+ members doing? mostly highway? it's very likely.

is this program politically motivated? could be. do they manipulate the rules? possibly. is this an unfair entitlements program? i believe it is!

[Kiwanda]

The TDI rating really didn't make any difference in your case-- the upper limit for the clunkers is 18 mpg under the revised EPA ratings, so your Acura doesn't qualify regardless. They should have set the program up based on a % increase over your clunker, with the rebate increasing with efficiency.

They didn't though. Lucky for me I had a minivan with a failing transmission that was rated at 18. Now I have a new TDI and have more than doubled my mpg on the first tank.

[FrankBurns]

I traded off my beat up 90 wrangler on the first day of the program because I knew there was no way it would last for more than a couple of days or that it would not somehow be messed up. EPA average on the Heep on day of deal was 16 MPG. I traded it on a new Patriot, it showed a EPA average of 24 MPG. Being a SUV to SUV trade I only had to improve by 5MPG to qualify for $4500.00. Then what a surprise, by Tuesday the following week the EPA determines that they need new fuel estimates for the qualifying vehicles. The old wrangler showed improved mileage up to 17.6 and the new Patriot went the other direction down to 22 MPG. This meant that if I went to make the same deal today I would qualify for $3500.00. EPA averages in no way reflect what individuals may or may not obtain in real life, it is as stated, only an average. However, some cars that did qualify suddenly did not on one end or the other, or would only qualify for the lesser amount.

Cheers.

[bates]

Mathowie,

You are correct, this did come out sounding more like a rant than I had intended, I was incredibly frustrated by the situation and truthfully, yes that last $1,000 was sort of the difference between the offer making good sense to me financially and the decision to hold off on a new vehicle purchase. Thank you for your information and input. It was not my intention to make this site a political debate discussion, I am sorry for doing so. I realize that there are plenty of hyper milers who skew the figures, but I also remember owning a 1980 VW Dasher Diesel back in the late 1980's that got 50 MPG or better with me driving it and I would have to believe that as technology has improved over the past 30 years so should the mileage.

Kiwanda,

You are absolutely correct, when I continued my research I found out that 18 MPG was the bottom benchmark for eligibility to the program. Thank you for pointing this out. I agree with you completely, that a % increase or some other method would have been a much better factor for deciding eligibility.

FrankBurns,

I'm glad to hear that you were able to get in before the mileage figures began to be manipulated. This just goes to support my argument that the EPA is playing around with the numbers to the benefit of some and the detriment of others. Clearly in your case the numbers were adjusted to put Jeep products at a disadvantage by increasing the numbers on your trade in and decreasing them on your new purchase.

[alnmike]

Also keep in mind that for every hypermiler, theres about 20 of us who dont. I enjoy my 50mpg trips into town, but my average is still hovering below 40.

[mathowie]

I would have to believe that as technology has improved over the past 30 years so should the mileage

Yeah, I in the same boat as you -- my wife's 1989 Honda Accord got low-30s MPG, but new Accords are a few miles less per gallon and it was sad to think we didn't progress.

But doing a little research reveals cars weigh much more due to much improved safety and engines had to get better to push all that weight around and not feel sluggish. So it's much harder to produce a big, safe, powerful, and efficient modern car.

[MarkShort1958]

Yes, there are many Jetta TDI people now on this site. More of the higher mpg acheivers in the Jetta TDI class, however are from owners of older diesels. If you use the filter available on the model guide and just select 2009 Jetta diesels, you will see that there seems to be a peak at around 39 mpg. Those driving older Jetta TDIs are usually getting better gas mileage than newer owners like me. I am not surpirsed as there had to be a 'cost' for the cleaner version of the 2009 series, and am nonetheless very happy with my mileage and the knowledge that I am somewhat more 'green'.

Actual mileage will always depend on your driving style. This makes it tough for anyone to give a single number for what individual drivers should expect. The new EPA guide does a better job of disclosing both the average number to expect as well as the range that is possible. 2009 Jetta TDIs are rated 30 city/41 highway BUT the range under each are 24-36/34-48.

I don't consider myself a hypermiler, but I do drive very conservatively. On my '09 Jetta TDI wagon, I am averaging just under 50 mpg using the same driving techniques I've used for a decade. I am only slightly above the maximum mileage that EPA predicted under their best case scenerio (admitedly mine is for a mix of highway and local driving whereas their 48 mpg gallon was for highway....).

In my mind, the EPA guides have been a useful tool to compare the efficiency of vehicles on a side-by-side basis and the newer guideline seems to be better. I really appreciate this site to see other techniques that might improve my numbers further (without coasting behind semi-trailers, thank you very much).