Paccar MX13 Fuel Mileage, how can I get to 7mpg?

An overhead should have an immediate improvement it that was the problem. Other than suggesting some after-treatment issues or plugging. I don’t know any thing about the MX13.

Only other suggestions would be to look toward an alignment issue with the truck or trailer...

 

Needs a different file in it. Werent you having a bunch of other issues related to the improper programming?

 

The paccar in my 579 is very efficient upper 7s low 8s fully loaded. Truck seems happy at 1150 to 1250 for rpms with the pacar 12 speed that puts me between 65 and 72 mph. 68 is about the best cruise speed

 

I drive a 16 Pete 579 and am averaging 6.8 mpg pulling a 48' split axel curtain side up and down interstate 5 thru WA,OR,CA. I set my cruise for 58 in CA and 60 everywhere else. Usually in the 75k - 80k gvw. What speeds are you normally driving and where is your normal running areas? I can usually pull out a .5 mpg extra if I don't use the cruise control and keep the boost under 20psi.

 

I run all 48 pulling dry van. My truck is 2020 ultra loft. Weights vary but I usually cruise around 68 to 70 mph which puts me running 1200 rpm. This is full paccar powertrain. Take it easy on getting up to speed and use the neutral coast as much as possible. Upper 7s are easy. Just averaged 9.1 from indiana to Kansas City running 65 mph most of the way. 25k in the box

 

This was California driving I 15 i40 running 55 the whole way till I got in traffic. Took pic when I seen it an we were going slow. Load was about 15,000 not heavy but still impressive numbers.

 

Ride the hills, don’t use cruise control until you’re at cruising speed and accelerate with up to half throttle. I usually get 7-7.2 mpg taking I-70 from Kansas to Ohio and I haul beef loads which are always as heavy as legally possible. I drive nights also which help avoiding all the traffic and sudden stops when passing thru big cities.

 

Make sure your using oem only filters. Keep your egr/aft system clean. Make sure engine,can softwares up to date. You heard of an mx special ?