Trip to Albuquerque, NM

Filled up just before jumping on the big road, I-10, in El Paso, TX. Drove up to Albuquerque, NM. A/C off, fan on 2, fresh air vent open. Left around 11 A.M. Drove the speed limit. Got 50 MPG (consumption MFI). Straight pipe mod, EGR & cooler delete. 2.5" from the turbo back. Stage 2 Malone tune. HP race intake.

On the return, I only got 48 MPG(consumption MFI). I had the lights on and when I got cold, I turned the heater on. When I got hot, I turned it down to middle of the temp dial. Turned the fan down to 2.

I guess with the drag on the alternator for the lights, is what dropped my mileage down two points. Maybe the cold air was a problem too.

Being that diesels operate most efficiently at 80 degrees F. An instructor in tech school told me that. It was in the 60's on the way up there. In the 40's on the return trip, at night. As I got closer to home, the temp went up to 51 degrees.

At 11 MPG(hand calculated) better than the stock MPG on the way to and from Ft. Worth, I'm happy with my mods.

6 spd?

Darkhrse99 said:

6 spd?

Click to expand...

Yes, it is.

Would be curious to learn about the "diesels operate most efficiently at 80 degrees F". Quick search didn't bring anything up about that. Is that for normally aspirated diesels or turbo? I'd always heard "warmer engine, cooler air" (up to reasonable limits) would provide for better diesel efficiency regardless of outside temp, especially on the turbo diesels. So an engine warmed to operating temp but with intake temps near/at ambient would be better. To keep engine temps up in winter, we have the "winter grill blocks" and to keep intake temps down in summer, we have bigger/more efficient intercoolers.

I can't imagine headlights or seat heater affecting MPG at all. Maybe it does idk...... +/- 2 mpg is probably diving style/conditions.

I can't even tell a difference with a/c on or off when doing hand calc for highway driving. My best tank ~700+ miles was done with full A/C most of the time, two people, and 3 days worth of clothes and camera gear. 50.7mpg hand calc on that tank IIRC.