Wow! Superchips programmer
 

Got a free Superchips programmer for the GMC. Computer is saying I am getting about 4 more mpg than stock. Gottta take a lil road trip and see. Averaged about 13 last trip lifted on 33's. Now I'm showing 16 and 17 on the instant mpg. I hope it's true. Also like the extra torque. Feel a real gain when getting on the freeway. Time will tell.

Don't trust the Lie-O-Meter, hand calculate. I wouldn't be surprised if you are getting worse mileage.

I don't want to sound like a dick, but I doubt u are getting 17mpg with a full-size on 33s. If you are, i'm going to need one!

The overhead computers are optimistic to say the least. Always hand calculate you're fuel economy. My 07 Dodge Mega Cab 5.9L diesel 2WD gets 19-20 hand calculated (3/4 hwy driving) with Smarty Jr programmer on 285/50/22 (just over 33")Nitto Terra Grapplers. Other mods are AFE Stage II intake and Aero-turbine exhaust. Prior to the mods I was getting 18-18.5 hand calculated. Towing my Moomba XLV is more like 14mpg

AJ if you had a 4" lift, 35's, Afe exhaust, volant intake, smarty sr, 1 piece aluminum driveshaft, and 4x4 something tells me you'd get 15-17 mpg and 12 towing ;). I've got an 06'.

gas or diesel? 13 sounds like gas, i average 17 in a 2000 7.3, some tuning and exhaust would bring it up

My 2WD 5.9L mega cab is actually lowered 2"

I'm not sure about gas mileage differences, but you'll feel substantial seat of the pants improvement with tuning because it eliminates a lot of the torque limiting that the stock tuning provides during shifts and in 1st gear (from what I understand).

If it's got the 6 speed you could theoretically get 17mpg with 33's. If it's a 4 speed I'd expect more like 15 on the highway.

I'm going to fill up tonight and see what it comes out to. From what I can see as far as miles per tank it is by far better. Have to see how many gallons she gulps down at the pump for sure.

Evan,
You hit the nail on the head for my Tahoe. I was lucky to get 15 hwy with the lift and 18x33x13.5 on flat ground and no wind.

i have a 06 chevy diesel w/ a 6" lift running 35's. as far as mods i have a ppe programmer, afe stage 2, 4" exhaust from the turbo back, banks intercooler and get 22.3 mpg. i took the boat in for repairs about 2 hrs away, dropped the boat off set the cruise control and returned home going 63 mph.

332 miles and took 20.6 gallons of gas. = 16.11 mpg. Pretty much all hwy miles. I can live with that.

Looks like you gained alot but you should have hand calculated before the programmer to find the real gains/loss

regardless of the "hand calculated" values vs. the onboard avg. mpg you can still figure out the difference of w/ a chip and w/o just by looking at the dash. i have a super chip on my yukon and it makes the thing so much better.

what's the point of a lift anyways? doesn't change your ground clearance much at all

I did calculate before and after so its pretty spot on. Going to keep track for a couple more tanks and see.

If you know what your doing off road a lift does make a huge difference.Gotta know where to put your rubber to crawl over stuff. Now deep mud is another thing. If there is no bottom well your hosed no matter what.

I think the point of a lift is to allow you to be able to run bigger tires which does change your ground clearance.

I just got a jeep and I think I need one of these programmers. The thing needs more throttle response.

What superchips do you speak of?

I have a superchips 3815 flashpaq for a dodge 4.7 or Hemi motor for sale if anyone is interested. 100.00 bucks and its yours.. adds power, better fuel ecomony, tow mode etc..

Let me know if your interested
extremeisaac@yahoo.com

The cortex is what I got. So far so good. You can do fuel economy, tow, performance 82 oct 92 oct and a lot of custom settings for tire size, rev limits, shift points and so on.