Fuel milage problem

don't accelerate so much. Try to keep an even speed. Try to avoid rapid stops.
try to avoid stop and go traffic.

Change your air filter more often. Change your fuel filter more often.

Check your tire pressures more.

I was having a similar issue with my DD15 in a Cascadia. I started to use Lucas Upper cylinder lube w/ injector cleaner. I idle a lot better and started to get better mileage as a result too.

But at least I don't have a miss in the engine any more like it did.

 

I know a driver that's averageing 8 mpg because hes 55 mph Phil no matter what.Thats not his name,thats just what I call him good ole 55 mph Phil,lol.

 

was the 5.6 mph before the service too?

What are you running for tires? Good for mileage? lugs? Ribs?

 

what do you have for gears?

What is the RPM at cruising speed?

 

sure you ain't driving my cascadia?

09 cascadia, DD15, 10 Speed OD, 3.42 rears.

I struggled to get over 5.8 mpg with this truck. It ran like crap, wouldn't pull a hill and rather puked.

I talked to one of our other drivers. he said to drive it like I stole it. If it weren't for the fact he's also getting 7.4 mpg and one of the highest averages in the company, I'd have laughed it off.

He drives a 2011 model truck though with a 10 spd direct.

The other tip he suggested....

Start up shifting between 1500 and 1600. Don't lug it under 1100 RPM when you are upshifting and getting into the next gear.

Down shift at 1100-1200 rpm.

I started to do that and it helped a little bit but I was still frustrated. It was driving down the interstate in WI one day I realized I basically had a miss.

If I couldn't do something while I was out, I was going to write it up when I got in that week for it.

I started to use Lucas injector clean that day and the miss went away and the hills started to pull a little better. I wasn't taking 9th gear as much anyway.

My mileage is also into the 6.2-6.4 mpg range now more consistently even with 43,000-45,000 lb loads.

 

so lucas is the trick, eh?

with my recent turbo issues. my mileage would drop to 4.

liquid muscle would always get me back to 4.75

now i've got a rebuilt turbo and shuttleworth high flow muffler waiting to be put on the truck. liquid muscle is hard to come by. would like to get something in the tanks to start cleaning out the injectors and maximize my performance and mileage right off the bat.

this truck needs to start making money again. BADDDDDDDDDDDDDDDDDDDDDDDD.