Mileage/Biodiesel Questions

Please humor me a few more newbie questions.

(1) I pulled up to a diesel pump today that indicated on the pump that it contained anywhere between 5 and 20% biodiesel blend. Since, if I understand correctly, VW doesn't approve of anything above 5%, I left and went to another filling station. But that made me wonder--is every bioblend clearly labeled with bio content? Because I almost didn't even see the sticker at that station, so it was something of a "close call". I guess I should have done my research on this point before buying the car. I had thought all the talk about using biodiesel blends were things that owners were deliberately adding themselves. I didn't realize that high-bio blends might come out of standard filling station pumps. I'm okay with the fact that I'll ruin my car if I put gasoline in it, but it's a little much to think I might also damage it using regular commercially available diesel from a filling station.

(2) My fuel economy is WAY below expectations. I've got about 1450 miles on the car, almost 100% of which is interstate driving, but I'm only averaging 35-38 mpg. The car is rated 42 and I was told would do better than that. I have driven it very aggressively so far but I don't think that should drop fuel efficiency by quite that much. Is this just an issue with break in?

Can't answer you about your FE except for external temps etc. Nobody on this web site has reported that any blend of 5% bio and up to 20% bio has harmed their engine. I have run B20 in both my 2010 JettaSW and now my 2014 Passat without any signs of problems including oil dilution, ie increased oil level in the crank case or poor performance. If anybody has please chime in.

The mileage will get better after 10,000 miles (more or less) and when spring get here.

Buy your fuel from the pump(s) marked D2. If there is some BIO in there as well, don't worry too much about it. But try to buy D2 (with a little BIO), not the other way around (BIO with a little D2).

Drive more, Worry less.

Bill

40X40 said:

The mileage will get better after 10,000 miles (more or less) and when spring get here.

Buy your fuel from the pump(s) marked D2. If there is some BIO in there as well, don't worry too much about it. But try to buy D2 (with a little BIO), not the other way around (BIO with a little D2).

Drive more, Worry less.

Bill

Click to expand...

Bill please explain Bio with a little D2 would that be B95? I doubt the OP will run into that do you? B20 is a lot of D2 with a 20% of bio, Still a little bit not a lot.

BIO with a little D2 would be any blend where the amount of BIO predominates over the amount of D2.

People actually seek out high BIO blends (even straight B100!)... even though they should know better than to run that in one of the newer TDIs. (Run what you want, guys.. we don't care what you do to your own car, OK?)

B2 is supposed to be the sweet spot regarding benefit/cost.... been beat to death here.

VW states (for years now) that B5 is the highest approved blend, but they have given their blessing to the state mandated B20 blend in Illinois. If the Illinois B20 blend is OK, then commercial quality B20 is good nationwide, it is just not official yet.

I'm pretty sure that commercial BIO costs more than D2 right now so if the sign on the pump says 'between 5-20% Bio'... is will run closer to the 5% simply because of the cost.

Bill

So B20 is probably fine to run in my car but may void the warranty. Lovely.

Here in IL, most, if not all the major fueling stations state 5 to 20% bio also. The only exception I know of off hand is Meijer's, which has straight D2. I've used the 5-20 mix with no ill effects.