So you're telling me that everyone of you guys on this thread here dont think that by getting rid of the very restrictive factory exhaust and putting a straight pipe in its place and every one of y'all put a tymar intake or a cold air intake of some sort and at least replacing the some of the IC pipes for you sd guys and upgrading the turbo doesn't provide better fuel mileage? What do you guys think they are there for looks or something? Any kind automotive mechanic will tell you that by increasing airflow that its makes it easier for the engine to do its job therefore making it more fuel efficient LOL.
Welcome to 2007...no.
Everything you've been told, read in a bank$ ad, or saw in a magazine is ***kin horse****. Sorry, but no you are so far off of what really happens that you wont know where to start.
While I was able to get my best mpg in my 00 ccsb on 35s in the race tune it had very little to do with the tune. It was all about how it was driven.
I ran stock fuel, oil, and turbo with php tunes and could sneak up on 20mpg riiight after a thorough servicing but as the fluids wore in the mileage rapered back off. Empty(still had a ton of chit in the bed, literally) it was around 15. Here's the catch, you wouldnt have enjoyed the ride because it was painfully slow for that reason. Running 3.73s and two lane highways coupled with a 37 I would lockout od to keep the rpms alive somewhat and shift into od on the 65mph roads. Then the mileage drops there...
Now im running 35s with muuuuch more power, air, and fuel and mileage is 14. I changed my approach. I have one tune, it is wimpy at 1/4 throttle and at wot it gives all the fuel there is. I simply push the pedal so the truck isnt burning rubber or smoking all over(which isnt an issue with a bb charger) and get to the speed I want and then backout. If I drive it how I enjoy to, its 10mpg.
If mileage is your goal, leave it stock. Driving like a grandpa is the one, the only secret to decent mpgs. Hate to tell ya but 20 isnt doable in any 4wd lb cc truck even with stock tires. Maybe 17. Again, dictated by driving style.
We used to have an active mpg forum elsewhere and if you saw what it took to achieve 25mpg in a 2wd psd you would feel foolish for asking while owning oversized tires. Aint gonna happen bucko.
Ive driven my 7.3 all but a handful of the 260k miles on it. I got it new. I know a wee bit about mileage. Stock, lifted, leveled etc...