6.4 maintenance costs

I have a guy I know that I have done some work for that is selling his truck, needs to cut some bills his wife lost her job. Truck is a 09 cclb one ton fwd xlt, has had exhaust done, no dpf, intake and a spartan tuner with a variety of tunes, 4 inch lift with like some 37's "that will be coming off for mileage purposes.
My questions are what kind on mpgs can I expect with stock suspension back on? Owner says truck gets around 15mpg the way it sets and I don't think he has a economy tune on it also all around maintenance costs, guys are so full of **** on mileage you hear anything from 15-22 I mean can't be that much variance?
I drive an old first gen powerstroke and the 2 reasons I keep it are its paid for and its predictable on maintenance costs and very reliable, sorry three resons there. Been thinking about buying a newer truck and this one is very slick and I have liked it ever since owner got it and I know I can get a good deal on it, any info appreciated thank you ,john

Nothing guys? I could really use your opinions here, I need to make a decision by tomorrow, thanks

Hey man. I say he is damn close 15mpg is probably dead on. I doubt you will see much better no matter what with the 37s. The 6.4s get better mileage with bigger tunes, so economy tunes arent really for economy lol. As for the maintenance, they are about the same as your truck. With no dpf it will be more reliable. Really all you will need to do is change the oil and other fluids. Since its a common rail, the motor wont be as picky about the oil you run like the HEUI trucks (as a rule). I love my 6.4 and havent had any problems. I have done 2 tranny services in 25k but thats just cuz I beat on it. Other than that watch the fuel filters as they need to be done every 15k and they are like $75. I skipped over the stock suspension part. You may see up to 17mpg with stock suspension- but I wouldnt expect more than that. Ive seen as much as 21 on the highway at 70mph- it all depends on your driving habits.

Thank you jdgleason, I appreciate the info. This truck is a peach and only has around 30000 miles on it and the stock suspension is definately going back on with a leveling kit. Truck has never pulled anything heavy and no gooseneck hitch either. What brand of oil and filters do you use jdgleason? It is funny about the oil my obs only likes the "powerstroke" oil it hates rotella.

i dont see much better than 16 mpg with my truck either, when it was lifted it was about the same as it is now with injectors ect.

As far as maintainance fuel filters are a little more expensive than other trucks but the oil and oil filter are about the same cost

Sure thing. Sounds like its a truck that will treat you pretty welll then. I got an oil change package thrown in when I bought the truck, so it goes to the dealer for oil changes every 2500 miles. Lol I figure if Im not paying for it, why not right? But I buy the filters and fluids from the dealer anyway. then my ace is covered for warranty issues, and I know its all spec'd. One thing about the tranny- make sure you only use the ford spec'd mercon lv. Normal tranny fluid will toast the 5r. And another thing to note- the 5r is controlled by solenoids, not a valve body, so it can be picky as well. So, I may not be the best subject since my truck has been a dealer baby, but I will say I have never driven a truck that drives like a 6.4. The power, response, quietness, lack of smoke, etc is unlike any other truck around. youll love it

i'd say go for the 6.4, you'll love it

Thank you guys, very appreciative of the intel! What are the common issues if any with these motors?

Hmm. Id say most common motor issue (minus the dpf) would either be egr failures or an injector hang open. Either way, they are not super common. If you want the truck to be super reliable, delete the egr and keep up on maintenance. Youll be fine.

Thanks jdgleason, I think the egr delete has been done when the exhaust was done but will find out later. I am good with proper maintenance, that's how my old 96 has gotten me this far, thank you for the info man, by the way what do you use on your truck for fuel treatment? My old truck has always gotten howe's, every tank in winter, every other tank in summer or power servicealso.

I use power service, but probably every 5 tanks I would guess. I make sure to drain the fuel water seperator frequently too.

I run power service every tank. I thought you guys did the same? Guess I am kind of wasteful. lol

Wow. You guys must get crappy fuel. I never use any fuel additive in mine.

To the OP. DPF delete, egr delete, and keep up on the oil changes. Water in fuel has never been drained on my truck, I know bad but the lights never come. Good filters, good oil and your good. Oh vent the crank case vent to the ground to avoid coating the entire intake in oil.

I dont get crappy fuel at home, but when i travel thats when the water light comes on.