bigfoot

I have been thinking (sometimes that can be dangerous) with fuel being as high as it is. If a fueling box were available that would decrease HP. My thinking is this; as long as I’m running empty I don’t need the extra HP and could turn the fuel down and save. When I hook up to a trailer or load heavy I could turn the fuel back up to full factory HP.

I have not found need for more than factory HP. But would not mind saving a few bucks on mileage when I could. Anyone have any thoughts on this?

CTD NUT

A brick UNDER the accelerator pedal should do the trick.

Seriously, this might be the wrong site to discuss how to DECREASE power. If my priority was mileage, I'd probably be driving a TDI Jetta.

Also, an electronic module that decreases output has the potential to actually hurt mileage since timing will likely be too conservative in order to decrease power which will affect the efficiency of the engine.

cumminsdriver635

Drive easier. Thats the only way i know to help mileage. When you drive easier, you are using less fuel. A small box that adds power(EZ,Van Aaken) will help mileage some if you drive right. Its hard to beat that. You have to realize that 20mpg is VERY respectable for the size these trucks are. Dad gets 20mpg consistently in the summer with his truck, but when i drive it a full tank he gets about 16mpg . Its all in the driving.

Eric

StrokeThisCTD

if you take power away, the motor will work harder to move your 7000lbs worth of truck. That is why most people see gains with a box as the motor is hardly working at all when modified.

bigfoot

Not to disagree and start a war. But the 1991 model truck that I had got around (give or take) depending on how hard I drove it 21- 23 MPG. This 2002 model with the same basic whistles and bells just a larger motor (160 HP V 245 HP) only gets 19-20.
Now I’ll admit that at times it is nice to have that power but looking at it another way, this is more HP than I had on my first road truck (190 HP Cummins and yes I know I'm old ) and I pulled a lot more weight with it than I ever will with this pick up. Now don’t misunderstand me I realize that truck had more gears and was set up different I’m aware of that and understand it. It’s just that it would seem that by lowering the HP and driving the same way that I do now (conservative) I would get better mileage. Just food for thought.

displacedtexan

But you are not comparing the same engine, 12v will bet better milage than a 24v... gotta compare apples to apples.

bigfoot

I stand corrected, was not thinking about 12-valve V 24 valve. Oh well as I said it was just food for thought.

mnengr

Funny thing is that Cummins and Dodge went to the 24 valve because it was more "efficient" yet it get worse mileage..... maybe there is something about defueling... or timing.... or ??? What changed?

cumminsdriver635

I have gotten 22mpg on the interstate running 75mph with my truck. I believe 23 is very possibly if i slowed down a little, and never once used the throttle to hard. lol When i got 22mpg, i still ran it hard a couple times. Plus this auto is pretty darn high with the 3:55's. Hard to beat a 12v though.

Eric

j-fox

I would like to try to advance the camshaft to get better mileage. Optimizing the the cummins is the first place to start. Some one said the factory cam is retarded in timing as related to crankshaft. This is one area that must be aproached with caution to avoid valve to piston contact.