24 Valve 5.9 Liter Dodge Cummins
 

I am trying to get more MPG and power. I have 4" exhaust w/power elbow and have a rebuilt injector pump (all codes are clear and has 15psi of lift pump pressure) My MPG is 10-12, does anyone have any ideas to get more MPG/power?

Yes, if you check my recent post, you may have a boost leak. It will cripple your mpgs and rob power. Just had one fixed and it made a huge difference. I mean HUGE! There is a way to do a leak test, poke around on this forum and you'll find it. Another thing is to take out your airbox and put a big air filter in place of the box. I bought a "specter" for $40 off the shelf and it fit gr8. Took about 10 minutes and added a lot of throttle response. It's a poor mans cold air intake but $40 vs $400 for the same results is worth it. It will work good with the 4" exaust. Next would be a tuner. It can be frustrating to figure out your mpg problems. A boost leak will tell the ECM to cut power to the motor. I was getting 12mpgs and after I fixed the leak and put the air filter on I'm @ 14-15 after one tank and I hauled 6000lbs of dead weight in the bed too. I expect better mpgs next tank! :jump:

You wouldn't have a part number for that air filter would you? I appreciate your help.

No but I got it off the shelf at autozone, it was the only specter they had. It has different adapters to accommodate all applications but you won't need those. Its about 10" long and will fit right in the end of the tube where your airbox connects. Just slide the end into the tube and tighten the hose clamp right on the air filter, I used a bungee cord cut both ends off and drilled a new hole on each end to fit the studs that secured the old box. Its a easy way to secure it. The "specter" has the same ratings as K&N but is $10 cheaper. It will double the airflow. You will hear the turbo working once this is done. I noticed 1/2 mpgs when I did mine but that was before I had the boost leak fixed. I'm sure the benifits are more than that in a properly tuned truck. Like I said a boost leak is your worst enemy. 10-12 is bad, have you replaced the lift pump? Or do you have a in tank pump? Do you use a fuel additive? I have noticed different gas stations give me different mpgs too. Pay attention to where you fill up and how many mpgs you got with that brand of gas. Mine varies up to 1 mpg depending on where o fill up. I found Gulf #2 diesel works best. I just started adding some 2 stroke oil to the fuel too. I don't know if it helps anything but it at least helps lube the vp44 and help the injectors not stick. I'm new to this but this site has helped me learn what to do. At 10-12 mpg it will only get better from here.

Please dont use K&N's and other inferior filters. Even more so if their oiled.
Not only will they come apart and destroy a turbo (not an issue if properly take care of. ) but the oil is of a thinner viscosity and will actually pull through taking silica with it.

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FYI exhaust manifold leaks will cause a greater loss in MPG than a boost leak

Keep in mind guys that the oiled filter can cause problems in the cummins and other turbo applications. not much experience with the specter but if its the one that im thinking of, its not designed for high suction/boost apps, the turbo will suck the oil out of it over time or the filter element will fall apart and that aint good.

Now, for the MPG thing, it could be a boost leak, it could also be a restricted fuel filter, when was the last time you changed your fuel filter?

Also check for fuel leaks while running, pay special attention to the top of the fuel filter housing and the lines to and from the injection pump.

What filter would you recommend?

AFE, the dry one or the BHAF

Ab afe dry drop in is super easy to clean and high in quality. There are some studies floating around comparing filtration, cost and durability of aftermarket filters