Mileage burning #1 vs. #2 diesel

[Mark Rinker]

So...I have been under the impression for some time that the BTU content of these blends are the same. However, on the occasions that I have filled with #1 diesel in warm weather, it seems that my average MPG on the DIC begins to climb.

Yesterday I drove unloaded about 180 miles, filled and realized I put in #1 diesel. On the way home, same speed, I added about 1mpg to my average.

Coincidence? Factual? Maybe a tailwind on the way home, instead of a headwind?

[DennisG01]

Well, Mark, now you've got me scratching my head! I had always thought that the (very basic) difference was that #1 had slightly less BTU's, but also does not gel as soon. ???

[bshull]

I was under the impression that #1 had less wax in it so it could resist gelling better at lower temps. With the lower amount of wax came lower BTU per gallon.

I am sure someone will chime in and set the record straight.

Brian

[rapidoxidationman]

the Mercedes forum, Dodge forum, Cummins forum, and some others say:
less BTU's/gallon (137,000 vs 142,000? ish), less paraffin so won't gel as soon, less lubricity because of less wax, costs more, poorer mileage.

Methinks you had a tailwind...

[Mark Rinker]

I think it was a tailwind, and a lighter foot on the way home. Average for the 400+ mile day was 19.2mpg unloaded. Not bad!

[tufcj]

On my 2003, I see a noticeable drop in mileage (2-3 MPG) between November-February when they sell the winter blend diesel here in the Denver area.

Bob
tufcj

[More Power]

Hard to gauge what effect it might have for just one tank of fuel, but #1 has less fuel lubricity and can increase fuel injection system wear when used in warmer weather. Here in Montana, we get winterized fuel (mix of #1 & #2) through about April 1st, and am always glad when the pump indicates straight #2. Jim