BigNick98

Hey gentlemen I need some advice on an issue I've been having for a few months. My truck is getting horrible fuel mileage for the mods I've done. 12 mpg highway just isn't cutting it and I'm not sure what else to do.

I have a 2012 xtr 6.5 bed with 3.73 gears and max tow package. Truck had 45k on it when I bought it. When I bought the truck I was getting 15-16 mixed driving. This was with winter fuel.

Next comes the mods. I proceeded to do a 93 performance tune from unleashed, a 4 inch exhaust, aem filter, and put brand new Motorcraft plugs at .28. Now it's summer time and I'm getting 17-18 mixed driving. Now I'm in the 50k mileage range.

Here's where the problem begins. I start to notice that the truck is having an issue coasting. I let off the gas and it immediately starts slowing down. Even on a steep downgrade it will hold steady at the speed I'm at. Truck now has 59k miles on it and I haven't changed anything. Tires are still good, cleaned all the map sensors, and brakes are good. But I'm still having a coasting issue which I'm assuming is contributing to my horrible mileage. Even on a highway trip I still can't get over 12 mpg.

Any and all input is appreciated. I don't want to turn to my dealer but I'm beginning to think that may be my only choice.

paintballdude05

Start with the basics, service brakes, parking break and tire pressure. Sounds like you have drag in the drive system which is robbing power.

BigNick98

That's what I was thinking also. Checked brakes. Never thought about parking brake though. Tires are 35 all around like recommended.

Tothemax

Sounds like a brake hanging up.

BigNick98

We'll my carrier bearing exploded tonight. Think that would be my issue? Lol

Tothemax

Possibly.......