I have a 05 Pete C15 475 turned up to a 550, twin turbo 13 speed 3:55 24.5 rubber pulling a bullwagon, cant get over 3.8 mpg, no matter if i run it easy or run the dog #### out of it. I have plenty of power with either 90,000lb or 33,500lb i gets the same... I am getting plenty of boost.. bout 63 psi. What can we do to it to get better fuel mileage, i know the rack aint helping

Talk to Mr Haney and get a PDI tune. Replace the stock mufflers if you still have them. Make sure your not losing boost anywhere. Also make sure your not losing drive pressure through a exhaust manifold leak. If it is leaking at the manifold I would put a PDI manifold on it. I gained over a mile per gallon with those changes and it runs soooo much better.

If you go see Mr Haney leave the trailer at home I am sure he'll thank you for it.

Originally Posted by bullhauler11

I have a 05 Pete C15 475 turned up to a 550, twin turbo 13 speed 3:55 24.5 rubber pulling a bullwagon, cant get over 3.8 mpg, no matter if i run it easy or run the dog #### out of it. I have plenty of power with either 90,000lb or 33,500lb i gets the same... I am getting plenty of boost.. bout 63 psi. What can we do to it to get better fuel mileage, i know the rack aint helping

I use to pull bullrack with mine, and I only ever saw numbers that low when it was below zero outside with wind. I averaged 5mpg with mine pulling a triple axle up to 96,000. I think you have some underlying issues that need to be addressed before you start doing any kind of mods to it.

When was the last time the overhead was run? Check the charge air cooler, fuel pressure, accerts are fussy motors. Also make sure it has the updated filter head for the fuel water separator.

Originally Posted by sicshovel

just pulled my fuel temp sensor off it has the 2 wires but they are a square plug, heres a pic of it and i stopped at radio schack today and bought a 5 pack of 150 ohn resistors to put in the end of the fuel plug, are these resistors directional? thanks

no they are not. bend the ends of the wires over so they fit tighter and tape it up. also tape the plug in the fuel housing so dirt doesnt get in.

I have a c12 cat , can anyone tell me if I can do the boost harness on my engine? I did the home made fuel temp mod and disconnected the waste gate. It felt a little more responsive. I am getting the same amount of boost 26-29 psi.