how do I get more mileage out of my truck

[Kroner]

Going to pick up my 91.5 D250 in the morning and I would like to start tuning to get the most mpg out of it. Im thinking 4" exhaust, some kind of intake. What can be done to the pump to increase mileage? Not worried about power as thats what my 96 is for.
Thanks Everyone.

[CumminsPride]

I say back the fuel screw out as far as you can and turn the idle up. Take it down some hp. That should add some serious fuel savings. Just don't pull out in front of any semi's LOL.. It will have a hard time getting out of it's own way.

[Kroner]

How about injectors? Would the 215s out of my 96 fit in the 91.5 motor?

[CumminsPride]

The injectors themselves are not innerchangable.The bodies will fit but the lines won't attach. I think the 215's are a 4 hole injector and I know the stock injectors you have in it now are 6X.009". These are a good fuel sipper injector in my book. Your milage is gonna be based on strictly how you drive it. You can crank the pump all out but if you pu$$y foot it you can still maintain excellent MPG's. But if you romp on it "once in awhile" you'll see reduced MPG's. The easiest way to make it a sipper is to detune the pump so you can't reduce your MPG's. The injectors and turbo are fine, I would just try to find a 16cm housing for it. I had a 91.5, it had a 21cm housing on it.

[PToombs]

16cm exhaust housing and a set of 190 injectors. Smaller than stock and more smaller holes for better atomization. More power and better economy.
I wouldn't turn the pump down. You need enough fuel to pop the injectors.
After that, drive with a light foot.

[Kroner]

Ok thanks for the replies. The 215s are 5x.010 tho.

[CumminsPride]

You could use the nozzles but would need to have them flowed and pop pressures set for true reliability.

[dpuckett]

I'd say drive it. If you get 20-23, it's good to go. If you get 16-17, adjust valves, check injector condition (I had a set that had 140K and were SHOT- clean and reset put me 4mpg to the good), lift pump output pressure under load, timing.

Get some gauges, and learn to drive by them. I have seen a 150deg drop in EGT by slowing down 3-4mph. Wont take an appreciable amount longer to get there, but can save you .5-1mpg for that stretch. EVery little bit helps.

Is it an auto or stick? No matter what you do to the engine, it is useless if the power/ torque arent transferred well through the auto.

Daniel

[redneckroot]

What kind of driving do you do? Highway? or around town? If you do a lot of highway driving I'd look into either a gear splitter or different gears depending on what you have in it. My 90 with 3.07's with a 727 auto was getting around 23mpg up to 65 mpg with 33' tires. If I went on the highway at 75 it wasn't so good.

[mprmn08]

up to 65 mpg? holy crap i need that truck.

[PToombs]

I think he meant mp hour.

[mprmn08]

ya but i still gotta give people a hard time.

[Kroner]

I just filled it up for the first time sunday so ill let you know what kind of mileage I get on my first tank. The truck is used to go to school and work everyday (50+ miles a day). I take mostly highways and get to run 50-60mph most of the way, I think there are about 5 stoplights the whole trip. Truck is an auto and has 3.54 gears. IM going to run a few tanks through to get a base mpg. My plans are to swap a 12cm housing in, bump timing and adjust the pump some. What would 3.07 gears do for me?

[PToombs]

Empty your pockets, if you could find some!
Hard to find, and expensive now. Ask Philip, he knows.

[921stgen]

Hey Kroner & pete here are a couple of places with 3.07 axles for sale: http://www.cumminsforum.com/forum/1st-g ... -07-s.html
, and a single in NY: http://www.cumminsforum.com/forum/1st-g ... rears.html