Help me with my C15 for better mileage ??

In 13th gear at 60 my truck is running at 1300 RPM's.... any slower I'm getting run over on the Interstate, plain and simple these things suck at fuel mileage, but you live and you learn, I just gotta adjust my business plan

 

My 05 acert so far this month has averaged 6.96mpg, driving 65mph on the cruise and the occasional hammer on it to get around someone else.

 

Can you tell us again what type of trl. , loads you're pulling ?
Is that with the Bully Dog ?
Thanks.

 

I pull a flatbed, average load weighs around 42,000lbs, run all over the eastern half of the country. I have the Bullydog and straight pipes. The biggest trick to getting fuel mileage with an acert is to keep the rpm below 1400 at all times, even when getting up to speed, they will pull strong all day long down to 1100rpm.

 

I run Donaldsons and they are a little bit louder, but more of a low rumble, but not enough for the average person to notice and with the Jakes, it was quieter than the cheap mufflers I put on it first. I also picked up between .4-.5.

 

First off, the bulldog is not going to help. When you said a shop checked the charge air cooler, did they the pull the boot off and blow smoke thru it? If not, they did not check your CAC. Have a good CAT only tech run your overhead. I have a CAT tech that works on mine after hours. Most shops just look at CAC and say, "Good to Go" if they don't air the system and blow smoke thru it, you'll never know. My guy made a tester himself.

You said the horse power was 435, and bumped to 550. One of the biggest problems most shops won't tell you when they bump up the engine thru the ECM is you need to change the base plate on your outside fuel filter. The one that's on it at 435 hp, is a 90 psi plate, restricting the fuel flow to get true horsepower. You need a 120 psi base plate, they only run around. $100. Or go to a FASS system (Fuel air seperation system) The FASS is well worth it.

I think there's a charge air system leak somewhere, but finding a tech that knows how to do a proper test is hard to come by. My C-15 Accert is a 435 hp, but turned up in the engine, not the ECM. I run the northwest mountains only, at 75,000-80,000 lbs, and average 6.3-6.4, and this is with bad RR tires. So it can be done. Good luck.

 

He's probably talking about Donaldson part # M100463 - I have them too, they're a good free flow muffler. Not loud at all in the cab. People tell me that from the outside it has a really deep tone that sounds great, not overly loud like straights. Some other members like the Walker brand free flows, don't know a part # on those. Really any free flow muffler over even straight piped is much better than the choked off baffled stock one.