Pete 379 with Cat C-15 mpg?

That is pretty horrible for grossing 90K! I grossed 88K once from Pittsburgh to central IA and was in the 4-4.5 range the whole time and that was even going through Ohio and having to stop every 5 miles and make a turn because of my routing. I really kept the truck running 55-58 in 12th gear once I got to IL and was able to hit the interstate.

Bayou, did you get your CAC and the whole intake and exhaust system checked for leaks? I still think you might have one.

 

64 I'm good on flat ground if I'm in the hills I'm screwed. Anytime I'm in the throttle I get 3mpg don't matter how easy you try and drive it scan gauge reads 3mpg I find it better to just get to speed and hit cruise control. I've slowed down to 55 one day and spent more time looking in the mirror I felt like I was going to get rear ended at any min I just can't do it....

I priced injectors last week and almost fell over $4,800 for a six pack...ya $800 each WOW

 

I checked it does it hold 30psi NO soon as you shut air off it's gone in six sec no major leaks I can find took soap and water in a spray bottle and drounded it even changed a few clamps, my exhaust is about to fully get redone think I'm going to do two Pittsburg mufflers and six out.

 

If you are loosing 30psi in six seconds, you have a major leak.

 

Get a single turbo, non-EGR powered truck. The ACERT sucks fuel.

My 379 with 3406E, 24 lp, 3:55 rears, and 13 OD, as of today, has an average 6.25mpg with avg speed of 60mph, over 2 years and 225000miles of recording it on the FuelGauges website.

Not great mileage but a 379 pulling flats has lots of drag.

Slowing down has kept it over 6mpg. It gets 5.5mpg at 65mph, and 4mpg at 70mph.

If I drove 70mph all the time, I wouldn't have two cents to rub together. Fuel conservation is key today. I don't haul loads that force me to run 70mph to get there on time; breaking even or losing money is not in my plan.

 

How much OD is that with and what other kinds of loads on your flat rockyroad?

 

I've called around to see if I can find a smoke machine I think that's the only way I'll find it.....anyone know a shop that has one??

 

How exactly are you testing it?

 

All shifts are 1150-1300 RPM and i run avg. 60 mph. also i use CAT 30 weight oil Lucas now offers it. BAYOU if your getting heavy soot around your pipes get your Injectors set, maybe a valve set too.

 

you have and MXS has CAT ever updated it? sounds to me your Auto Valve Timing is not sending you a code i had that problem it would see a hill and fall on its face the MXS needed an update to send the code...