It came with the truck, no idea where it came from before that.
^^^ This. The tires alone will cause some issues with economy, especially if you’re trying to calculate MPG off of a calculated number. On top of that, with the lift, you will experience increased air resistance by exposing some of the less aerodynamic parts on the truck. From what I have read and experienced, the powerstrokes have the lowest fuel economy for DD. That being said, people like them because they do work. MPG is definitely best in an older cummins 2wd.
This clearly isn’t going anywhere.
Sounds like he needs to do an accurate mileage calculation before we all jump to conclusions. FWIW i have an 06 dmax cc/sb 6" lift 35" tires, before i put the tuner and exhaust on id get around 15-16mpg. My uncle has the identical truck, 06 cc/sb but with no lift and stock tires and no programmer or anything, he gets 20 regularly. All similar driving conditions, mostly highway. So i figure the lift and tires cut out about 4-5mpg respectively.
My 07.5 6.7 Cummins gets 17/22mpg (city/hwy) hand calculated, stock height and tire size.
I will attack this beast this weekend. Thanks guys. Gonna get that speedo calibrated and lower my idle time. I do want to check hpop and that exhaust piece. My first diesel so I’m learning. Just wish my garage was bigger
BTW, the ULSD is not good for these things either no matter what people say. Some people use 2-stroke oil and my father in law uses marvels mystery oil to add some extra lubricity for the injectors and pump. Also, look into a FASS setup. I hear they help reduce wear and tear on the fuel system as well as help remove water from the fuel too.
the big tires are deff gumming up your MPG… A friend of mine had the 7.3L in his e350 van and he got 20-22 highway
The tune from the factory is different between the f trucks and e vans though. Also different transmission gearing too.
the van was a 95… pretty sure they both made barley 200hp lol
to add to this, for what its worth my work carries RBP diesel fuel additive if you are looking for something to add in your tank.
Put a call in to get alignment. Seems like the mileage has greatly improved after oil change and fuel filter/ water separator replacement. Need to rack more miles and get speedo calibrated. Anyone have that ability and some free time?