Why am I getting at best 14 mpg. I drive 80% highway. I have 05 6.0 powerstroke 4x4. 285/75r16 non lifted 65psi. I never get over 68 mph. I see a lot of post and people are getting 17. I ran diesel keen silver through last tank still didn't do anything. My ficm puts out 48.5 constant. My delta between oil temp never gets over 5 degrees. Would stiction cause lower mpg? When first crank it rump rumps a couple times and lines out. I ordered Rev x should be here in next few days. How do I tell what flash for ficm. I read that if it has latest flash it could get bad mileage. I would like to get at least 16mpg.

 

Winter diesel ?

 

You are not the only one with this issue. I think I have tried just about everything to get better milage out of my 6.0. Granted I am lifted and running 35's, but even when the lie-o-meter is saying 15mpg (like it did this weekend) the calculator is telling me I am getting 13mpg

I have tried just about everything I can think of to help the MPG. I am running the FICM Atlas 40 program, the SCT street program, All new bits and bobs under the hood, including a regulated fuel return system, Bulletproff oil cooler/filter, Bulletproof EGR, and more. I have recently done a REV X treatment and I run stanadyne at normal fuel-ups.

Nothing I do seems to help. Next on the list will be a custom tune, but after that I am out of ideas.

 

I lost mileage with mine. Either this was a coincidence or the issue. I cleaned the group of connectors on the drivers side fender (under the hood there is a group of connectors). I took each one apart, cleaned with contact cleaner and put them back together. Now my mileage is back. I get 16 in the city and got 19.5 on the highway, keeping 70 or less.

 

I'm in the same boat as you brother. I read posts on FTE and can't believe what some people are claiming for fuel mileage. I've got a stock height EX 7.3 and I'm averaging 13-14 around town and I just recently took a trip and averaged 16-17 highway miles. I'm hoping to squeeze a couple more mpg's when the weather warms up and just last week I added a TS 6 position chip and a 6637 filter.

 

I own a semi. Lots of people get .5 to 1.5 MPG better than I do. Suprisingly though, if we load at the same place and run together, it takes less gallons to fill my truck. (1 or 2 tenths MPG is huge on a semi with the miles we run) So know your MPG and work to make it better, other peoples numbers are useless and possibly BS. Right now it's probably winter fuel and increased idling because of the cold. You could try running some 2 stroke oil 1 quart to 100 gallons diesel to lube the injectors.

 

I'm on your ship, 12.5 to13.25 over a few hundred miles of mostly town driving, hand calculated.

Freeway is hovering around 17 at best.

Stock tires and suspension other than just added b/x codes. MBRP exhaust, edge cts programmer.....

 

I got my Rev x in today and poured it in. Next question it came with 2 fuel additives that say treat up to 25 gallons. Should I use 1 and get 25 gallons next fill up or use to and fill up 44 gallons? Would that be overkill 6 gallons less full than what it supposed to treat 50 gallons

 

I just dumped it all in and then drove the HELL out of the Ex until the next fuel up. I wanted to make sure that the 6.0 got a thorough workout while the Rev X was doing its job.

Anyways, that is what I did, was it the right thing to do? Who really knows...

 

That's what I'll do when I fill up next week. Use both of them

 

what does the rev x do?

 

Ive been fighting MPG blues also. Been seeing 9-10 in the city and 15 at best on the highway. Used to get a little better. Now I have a bad injector and looking at replacing all of them. Not sure if its a sign that injectors are not working properly. Truck has 130,000 miles with all sorts of upgrades including Eds Econo tune on FICM..

 

I thought injectors were supposed to last longer than 130K? Is that a 6.0 issue?

 

No clue I was hoping they would last longer but what can I say. Recently had some gelling in real cold weather. Not sure if some crap got past the filter and killed the injector or just my luck.

 

I've seen a significant drop in my economy as well. I'm not going to worry about it until the spring but I'll be searching for what I've lost then. I normally get horrible fuel economy in the winter so it's hard to access it now.