hey guys just thought i would gloat mostly cause my truck has never gotten better than 16mpg since day one, i recenlty adjust my timing from WAY to high to just right and took a trip into the mountains and got 21mpg and im stoked the amazing thing is my truck is lifted with 33's and only a 3 speed auto without lockup and i still got 21mpg yup these cummins motors are amazing when they are tuned right!!


jason

 

I thought advancing your timing helped you get better milage. How far advanced did you have it and how far did you back the timing off?

 

We're not talking apples to apples here--he's running a p-pump Those are some excellent mileage numbers for such an agressively tuned p-pump.

 

So I should have better milage by advancing my pump 1/8" from the block than I would with stock timing?

 

Yes and no. Advancing the timing leaves a bigger window in which fuel can burn before the exhaust valve opens. If you're already burning the available fuel with the base timing, mileage increase isn't likely. In the real world, the 1/8'' bum seems to net most folks .5-1.5 MPG. I doubt you'll match the Yukon in your sig...