I just wanted to hear from guys the use it alot on mileage, I took a trip to florida from virginia towing a flats skiff ( 1400 lbs) and averaged 16.5mpg on the way down but up in north floriday somewhere I stopped to fuel up and the station had B15 so I filled up with it and mileage on that tank went to about 13.3, it did seem to run smoother but whats the story with the mileage drop? if this is normal why would anyone pay the same price and get worse mileage? I know its cleaner but with fuel costs the way they i dont see the point. am i missing something?

just asking not bitching

From 16.5 to 13.3 is about a 15% drop, and I just can't see that happening as a result of B15. Even using pure B100 will only cause a 3-5% drop in mileage. With B15 there would only be about a 0.4 to 0.7% drop - not enough to even notice in a single tank of fuel.

Doing a little arithmetic - if 15% biodiesel caused a 15% drop in mileage that would have to mean that the biodiesel component had ZERO energy value (not it's typical 95% energy value of #2).

well I am telling you thats what it did, like i said before I am not complaining, I was just excited to give it a try as there isnt any close to me and I have read so many good things about it but I am telling you I got less than 250miles out of that tank an I had already run from virginia to north florida and filled up atleast two other times and hand calc both times before.

maybe I will try it again

but I just was shocked to see how much of a drop there was and wanted to hear if that was normal.

Have you done the trip using regular #2 since the bio? Maybe it caused the fuel filter to clog.that will surely drop your mileage. I use it alot and do not really see much drop, maybe .5 mpg towing and thats it. empty is the same mpg

well I am telling you thats what it did, like i said before I am not complaining, I was just excited to give it a try as there isnt any close to me and I have read so many good things about it but I am telling you I got less than 250miles out of that tank an I had already run from virginia to north florida and filled up atleast two other times and hand calc both times before.

maybe I will try it again

but I just was shocked to see how much of a drop there was and wanted to hear if that was normal.

Don't get upset. I didn't say you made the numbers up - just that it was unlikely to be the result of a B15 blend. You asked for opinions and that's mine, backed up with some numbers. I'd look for other reasons. Maybe the smoother running engine caused you to be a little heavier on the pedal, maybe there were cross-winds or head-winds during that leg, maybe you set your cruise a little faster, or maybe the shut-off on the B15 pump shut off earlier than normal..., or maybe all or none of the above.

I don't think B15 would clog a filter, but I suppose it can't be ruled out.

B-20 clogged my filter after a few thousand miles. Changed it and its been good every since. I need to change it accdording the DIC after about nine months & ??miles. I run B-10 in the winter & B-20 the rest of the year.

The other factor in mileage difference is elevation change. Going down to Florida, you had more down hill than uphill driving, and then going back to Virginia, it is more uphill than down. So if you were on Petro diesel you still would have had a loss in fuel mileage. Just a thought because I don't know the area.

I can't see how B15 would do anything. Technically, the BTUs in B100 are about 10% less than Dino. That reflects my own experience. I run B100 in summer and get 14.9 to 15.5 mpg. With dino I get 16.5 to 16.9. That's right at 10%. One tank's performance is not enough to be statistically valid. You'd have to run a couple thousand miles on each and then compare to form any conclusions.

thanks for the info,must have been a fluke, the fuel was from a pilot truck stop, all other factors were as close as possible and on the way home from islamorada to southwest virginia same load and cruise right around 72mph 5 tanks of fuel and around 1250miles it stayed around 16.0mpg

I will try it again next time I am near a place that sells it.

Jared

Maybe you got a bad batch of B15? I think that is the biggest hurdle with bio is consistancy. Many of the fellow members gave the same answers that I would have given!

It could just be the difference of weather or traffic also, were you driving into a headwind while using the bio? More traffic on the way home?

doubt had much to do with the way I drove as when i filled with the bio it was about midnight and there was very little cars on the road.