(Our 2005 Jetta TDI at the base of Mount Whitney. The VW has logged over 3,200 miles so far on B99 biodiesel.)
Two months ago we began running our 2005 Volkwagen Jetta TDI on biodiesel and now we have some preliminary fuel economy figures to share with you. Before we get down to specifics, I have to say that the Jetta has been used for more highway driving than its normal around-town motoring that kills fuel efficiency. So don't take these figures as gospel.
But first, a few thoughts on this German workhorse.
Last week, I took the Vee Dub up to Lone Pine, Calif., to do some climbing with a friend from high school. We drove up to the Horseshoe Meadows Trail Head at nearly 10,000 feet without losing a lot of power from the altitude. No doubt, the turbo charger helps offset the effects of the thin air by ramming more oxygen into the engine. In fact, I wish I had a turbocharger for my climb up Mount Whitney which left me doubled over and gasping for air.
A few days later, my friend and I headed for Death Valley and drove the Jetta in 110 degree heat. The needle on the temperature gauge didn't even budge. But on a long down grade into the Valley I missed having a car with a firmer suspension since the body roll wasn't confidence inspiring.
Now, let's do the numbers. Bear in mind that the results are not final since we need a greater variety of drivers and more city driving to really put the TDI to a realistic test. So far, after driving 3,260 miles on a combination of B20 (two tanks) and B99 (eight tanks) we have averaged 42.4 mpg. This is actually higher than petro diesel which delivered 39.2 mpg (which included much more city driving). So, obviously, we have to log many more miles before we get a clear picture of how the B99 performs. Still, these results are encouraging. And the only negative we've experienced using biodiesel is the clogged fuel filter we mentioned in an earlier post.
noflash1 says:
02:47 PM, 09/29/08
Why so apologetic?
You act like you are embarassed to get such good mileage.
This should be on the front page.
Embrace it.
Republican?
nf
jahfakin says:
03:46 PM, 09/29/08
only 42.4 mpg? You guys heavy on the go pedal? I use to get that in my 99 VW TDi, when I drove like I stole it. But the fact is, not all VW TDi engines are the same. It's the luck of the draw. You can have 2 cars driven the same exact way by the same driver. And the mileage could differ by a few MPG.
But the reality is 42.4MPG is very very good for any car larger than a matchbox. Not even the Smart car gets that.
misterfusion says:
04:18 PM, 09/29/08
Philip: I found that the best way to improve my performance on that Lone Pine hike is to only do it in the winter. ;)
Of course, that was in the days before my knees went all to hell. And even then, I only went as far as Stone House; I'm no technical climber!
joefrompa says:
05:42 PM, 09/29/08
I think he's so apologetic because he's qualifying the results heavily....i.e. like he said, don't take them as gospel but it's showing a nice trend so far.
It's amazing what this car is doing....we're talking Prius territory here, without any of the negative side effects. Of course, Prii are best in the city and the Jetta is for the open range. But considering you are doing some serious mountains as well, damn impressive.
Can we get a careful tank to show over 50 mpg? :)
Joe
brn says:
05:49 AM, 09/30/08
jahfakin, your 1999 (Jetta, I assume) TDI weighs 2870lbs and has 90hp (155ft/lb). The 2009 Jetta TDI is larger, weights 3280lbs, has 140hp (236ft/lb), and has tons more pollution control to deal with. I'd expect the 1999 to get a lot better mpg than the 2009.
So diesel is currently $0.94 more than gasoline here. That's gotta change.
firstwagon says:
07:34 AM, 09/30/08
brn
The long term test car is a 2005, not a 2009.
It has a lot more in common with the 1999 then the 2009.
karjunkie says:
07:50 AM, 09/30/08
"And the only negative we've experienced using biodiesel is the clogged fuel filter we mentioned in an earlier post."
Hardly a negative, since all the biodiesel did was clean out your fuel system. I view that as a plus!
brn says:
08:58 AM, 09/30/08
firstwagon, I'm a doof. I guess I was all excited about the 2009 offering.
I wonder how the 2009 is going to do. :)
autoboy16 says:
03:54 PM, 10/ 1/08
a longterm test can find that out brn! ;]