wow i really thought it might do better than this. i have a stock 2000 5.3, truck headers, 2 1/4 duals with magnaflow mufflers dumped before the rear axle. an AEM cone filter about 8 inches before it goes into the MAF and a 90 deg elbow after that into the intake.

i just checked my mpg's and i am getting 11.5 out of the first tank. i sent my computer to wait4me performance to be tuned for casual driving, with slightly firmer shift(which it doesnt have). i ran 89 octane, and i cleaned the injectors very well before putting it all togeter, it has new O2 sensors also. i am sure some of it has to do with putting my foot into it, but i drive 32 miles one way to work, mostly highway, so i cant run ti to hard. it has 3.73 gears and 31 inch tall tires.

any idea's, should i get a tune local using a wideband O2?

 

Sounds like the tune / driver.

What seep do you cruise at and do you have the cruse control hooked up?

 

That doesnt sound all that crazy to me. Most hummer h2's i see get an average of about 11-13 mpg on the 6.0

I get about 9 mpg maybe 10 on the highway going 25 miles to work, but see my mods in sig. aqs a result i never really take it anywhere far.

 

But his is a Jeep not a 3ton hummer there's a big weight difference.

 

Try running premium?

 

this isnt a 6.0 either. and its not turbo'ed. i cruise at 70 mph, that is 2k, with the TC locked up.

 

I get 15mpg with my truck. Something is wrong if you dont get more than what I do with a 3000 lb jeep with a stock 5.3.

Id get a different tuner, Ive heard a lot of bad things about wait4me.

Also are you sure your speedo/odometer is working correctly? Maybe its programmed wrong for your gears and tire size.

 

I get about 13 in the city with the truck in the sig, your tune is off or your foot is heavy

 

Try running several tanks the PCM might still be learning. Keep an eye on the mileage then if it doesn't go to at least 15mpg there is a problem.

 

my foot may have been slightly heavy at first, you guys know how it is. yeah some people love wait4me, some hate it. i dont have 800 or 900 bucks for a copy of hptuners and a wideband to tune it, and everyone that tunes is a ******* genius. they all have the best, or make it better than the other guy. its a freakin scam the way these "tuners" operate

 

You need a local tune. I know there are good tuners in KC. Check out www.mofbody.com and ask on there.

 

LOL, This has got to be the weirdest thing. I have a 99 GMC z71 ext cab. Came with a 5.3 I got 16 to 18 on hwy. with Shell 93. City 14 to 15 same gas. I put a 2004 lq9 out of a cad. and I am getting 16 city and 21 on the hwy with the 5.3 tune. ran 10.63 in the eigth with the 5.3 9.29 with the 6.0.

 

see if you can at lease get a scanner to monitor the system and what the sensors are reading..

O2 and IAC are a few of the key ones to watch.

 

what type of scanner would i be looking to get? any suggestions?

 

my 5.3 in the silverado gets at least 16-18 in the city

 

Hey man join the club, my wife has a bran new 08 tahoe an this has the DOD an it flat out sucks on fuel milage.Our 05 yukon had a tow package an 3:73 gear an it got 16 18 on the highway. Just my 2cents.

 

16-18 around town.. few stop/go situations.
Hiway well over 20.
1/2 ton, 07 ext cab.

Has the speedo info in the tune been set correctly? If not, the miles per tank, used in the calcs will be off.

 

see thats whats im saying, the tune has to be off, u still have 02 sensors on it?

 

I have a 2004 6.0 liter/ 4l60e with 3:73 gears and 31" tires in my 1999 Wrangler.

It's running on the LS1 tune. Had an LS1 in it. About 15-17 mpg.

Running 87 octane. I think a specfic tune for the 6.0 would do 18 mpg.

I used a Howell wiring kit and computer.

Jim

 

When I checked and got 15 I wasnt easy on it.

Most people that love wait4me just dont know any better. Everyone that Ive seen that had wait4me and took it to someone else or started tuning themselves, looked at the wait4me tune and laughed.