2005 Pete 379 c15 acert question

What size of rearends do ya have?

 

Is your engine an 1850 or 1650 torque? I'm assuming that it's 1850 with the 18 speed trans. Smarter people than me taught me that the RPM and boost are the main components in fuel mileage. With an 1850 475 the max rpm to get good mileage is 1350 and with a 1650 it's closer to 1400. Keeping the revs and boost down when running up through the gears and on grades will also contribute greatly to lower fuel consumption. With either engine there is little reason to ever exceed 1400 rpm, unless you feel the need to be Billy Big Rigger. I have a long sharp lookin' Pete that will run 105 and I get passed all day long while runnin' 63 - 64 by most everyone but that's what I need to do to keep my mileage in the mid 6's. And the same guys pass me sometimes 3 and 4 times in a day! Now that I got used to it I find my maintenance costs lower as well as my stress level. Anyway, I've brought my mileage up from low 5's to mid 6's. There are some inexpensive tricks and fixes to getting better performance and mileage from a C15 ACERT. You can find them all in this forum. The one with the best ROI is a muffler change.

 

No that wont hurt it. with a 475 peak hp is at 1400 rpm ( really its 490 hp at 1400 ) above 1400 hp comes back to 475 til 18 or 2100 rpm. depends on program in ecm. keep it between 1100-1500 rpm for best performance.
above 1500 your just making noise. splitting down at 1100 is a waste of time unless your topping the hill. if its a big hill go to 11-1150 and make a lever change. dont be afraid of the low rpm their quite happy there. it sounds weird if your not use to it. expiriment you wont hurt it. let us know how you do.

 

If anyone is interested I have a new acert MXS ecm 625 hp & 2050 ft. lb. 2300 rpm. You would see a improvement in fuel milage. Great improvement over the 475.. I also have boost and fuel wires........

 

can't pm yet, so could you post price on ecm?