With the superchip and the pretty big lift and tires at 50psi. I get around 14-15 mpg's but I'm not easy on her

 

That is part of it.
You are going faster now, which increases air resistance.
You are going farther than the odometer says, thus mpg "seems" lower.
Probably uses more fuel to get moving since effective gearing has changed, but it would be offset by better hiway economy from that new effective gearing.

Your city vs. Hiway ratio determines the net effect based on your driving.

Sent from my Sprint PC36100 using IB AutoGroup

 

Rough guess, about 12-14 city, 16-17 Hwy. Then again, the beast has 10" of lift and 42" Interco's. I'll know more accurate numbers once I perform the hand calculations at the pump.

I have an SCT tune (Performance), 4 inch turbo back exhaust and CAI. I don't speed.

 

If you do drive "normal" what mpg do you get? Reason I ask I may scale down my 42's to the 37's Goodyears in your sig.

 

Maybe 2 more mpg's. I'm thinking of switching to the Goodyear MTR a little better tire for what I do. Hopefully with not as much square blocks I'll get even more mpg's out of it.

But the MTR is almost double the price of what I can get MT for. I hoping the increase is enough to offset the price.

 

The one recent trip I took on the freeway...topped off before I got on and topped off when I exited....21.5 mpg. Totally stock...63-70 mph.

 

Hand calculated 17.4 mpg on my recent 630 mile highway trip at 73 mph. Around town I get 14-15 mpg.

 

best we ever seen on lie o meter was 22 or so, highway.

Is the muffler delete helping for mpg any? i never seen a reponse on that.

00 7.3 auto ex 4x4 stock tire size and stock wheels. stock height.

 

im only getting like 11 city. Is it because of all the stop and go and stoplights?

 

well...it varies...if you are towing you would usually get an average of 10-14 MPG, but if you are just cruising, then you would get an average of 16-20 MPG

 

I'm running a 6673 Mod, and AIH delete and a Superchips Flashpack Tuner. Best mileage ever, 23.9 mpg indicated on the Lie-o-Meter (mine actually jibes pretty closely with hand calcs)) running 50-55 MPH on the backroads with few hills and the ECM flashed to Max Economy over a 40 mile trip. I typically run with the ECM flashed to Max Performance and usually run between 75-80 on the freeway, that typically nets me about 17-18 in mixed driving. Towing a 8500 lb TT typically net 14-15 if I keep it below 75. Last "long" trip was a 800 ish mile round trip from Louisville, Ky to Steubenville, OH. Averaged 20.8 on the way there until I hit the hills near Steubenville. The combination of the hills and running to fast on the way home trying to keep up with the convoy brought the overall average down to 18.8 again with the PCM flashed to Max Economy. I just installed a TS six position chip, literally this afternoon. Two words come to mind, those being Holy and ****! Huge improvement in performance and drivability compared to the Flashpack and being able to change tunes on the fly with the "Go Mo Fasterer" **** is really nice when compared to reflashing the PCM, which I kind of wonder how often you can do that before you nuke the EPROM. I just hope the TS can deliver the mileage like the Flashpack.

 

 

2000 7.3 Ex 4x4 196k
285/75/16 BFGs
No lift
SCT street tune
10.8 by the lie o meter.
Mixed driving, highway not faster than 70.

There must be something wrong with my truck considering some of the above numbers.

 

Hand calculate is the only way to go. Be sure to factor in your tire size as well. Right now you have no idea what kind of mileage you are getting.

 

Some lie o meters are accurate and some are like a weather reporter. However, once you've hand calculated actual mileage, then use the meter as a benchmark. I'm no longer worried about fuel mileage, but do want to know when something is impacting fuel mileage.