[jgrayson81]

I have a 5.9 with some upgrades. I put on a bullydog gt,4"turbo back exhaust,cold air intake. With this I was getting about 20mph down the highway. I then added a airdog 150 an started noticing a lose in mph. Turns out I had a couple injectors going down. I had all injectors renamed with 100hp nozzles. The fuel mileage has never come back,the best I can do is 16mph down the highway. My mileage should have increased not decreased so I am looking for suggestions to what is causing this? I know a decent amount about diesels but am looking for someone advanced to help me figure this out. Any suggestions would be appreciated,thank you.

 

[DieselPlower]

Which mods do you actually think caused the loss in mpg? From the way you wrote it it sounds like you put on a air intake which does not filter the air well. It probably has done some damage to the engine. Then you put on an Air Dog, which i dont think filters as well as a baldwin pf7977 in the stock canister so thats probably where you damaged the injectors. Both of those things would cost you mpg. Then you put on 100 horse injectors..... Well theres another problem, obviously. Is it possibly also because its winter and you have longer warm up and more idle time? Maybe your running a different tune or power level and thats costing you too?

 

[jgrayson81]

I put on an afe stage 2 intake with an oiled filter. I think the airdog is the problem. Apparently I didn't realize that bigger injectors were a problem and would decrease fuel mileage.