Pump tweaks and O.K. MPG ??

[CAROLINA CUMMINS]

Does the mileage go down when you turn any pump adjustment up= more power. Or is there some sort of balance between adjustments?? As in max power, bad mileage,low power. great mileage, good power, fairly good mileage?







Steve

 

[Old Smoky]

It depends on how you drive. I have found that mileage remains about the same unless you constantly use the additional power. Sure, you will drive around blowing smoke to "test" your adjustments at first. But, once you get that out of your system, mileage should be about the same. With all of the modifications I have done I still get about 18mpg around town, and between 20 and 23. 5 on the highway.



Mike

 

[formula]

Right foot = mpg adjuster



If you add more fueling and have a heavy foot, then your mileage will go way down. I've always got about 16mpg. That's totally stock and even after all of my bombs. But if I drive with my foot in it all the time around town for a weekend I'll get more like 13. Take it easy cruising down the highway and I'll get about 20.



Cheers,

Sean

 

[formula]

Dang, Mike, ya got me this time



BTW, auto transmission will give you at least a few less mpg

 

[Old Smoky]

Ha! Gottcha this time! Oo. I think you're still one up on me though.



Mike

 

[nascar mark]

Originally posted by formula

Dang, Mike, ya got me this time



BTW, auto transmission will give you at least a few less mpg

Sean,

Actually the auto is rated 1 mpg better than the std from the factory. When I bought my truck new I walled around the stealer's checking it out.

 

[formula]

Originally posted by nascar mark

Sean,

Actually the auto is rated 1 mpg better than the std from the factory. When I bought my truck new I walled around the stealer's checking it out.

Mark,

You have caused a short circuit in my brain

I've never seen a mileage rating on a diesel at a dealer around here. They all refuse to discuss that topic. I made that statement based on experience. Of course, there are infinitely many variables that will affect the end result for fuel mileage. I am curious as to why the auto was rated better for mileage than the manual though.



Sean

 

[nascar mark]

My guess would be shift points and torque. I know it caught me by surprise as I have always seen std ratings higher than auto until our trucks.



mark

PDR - Black Sheep Racing

 

[Lil' Dog]

Is the OD ratio higher in the autos? Like 0. 69 vs 0. 72. Maybe that helps out.



J-eh

 

[Matt S]

From all the adjustments I've noticed that I can get a bigger swing between city and highway driving. I used to get 19 city and 20 highway. Now I see 18 city and 21 highway. I also noticed the slight drop when towing heavy. I used to get 17 and now it is 15-16. But as others have said, it all depends on the right foot.