99 /7.3 / Superduty / Crewcab / 4wd / Automatic / Auto-Hubs / 3.73 diff / K & N Air Cleaner

When I bought the truck new, I changed tires to BFG AT 285/75/16. Highway mileage was 17 mpg if I kept the Turbo quiet (60 to 65 mph) and 15 mpg at 68 to 75. After the first 10,000 miles, the mileage started improving and by 15,000 miles was at a solid 21 mpg and 18 mpg at the two speed ranges mentioned above. I was working out of town and making the 400 mile round trip every weekend. I put about 50,000 miles on it the first year and was happy with the 21/18 mpg.

I moved to Alabama on a job the next year and shortly after I got there, the mileage started dropping off. At 75,000 miles I was down to 15 and 13 at the two mentioned speed ranges above, and since then, it has not gotten any better or worse (AL for 3 years, back to TX in 2004). I just rolled past 200,000 miles last week.

I have had two dealers check it and both said "everything is in the recommended range". I asked both of these dealers and several others about getting the injectors serviced and they all say the same thing, "You don't want to do that, let us run some injector cleaner through it."

I don't want to spend a bunch of money trying to fix the wrong thing.

I'm looking for advice about what the most common cause for mileage dropoff is (mechanical and/or electronic related) and info regarding injector and injector pump problems and solutions.

Also, what does it cost to go through all of the injectors/injector pumps and get them serviced?

Thanks in advance.

 

i'd say you'd get a better response in the right forum. try moving to the 7.3 powerstroke 99 and up.