I put on the lift, and went up with tire size to 35x12.5r17, I also removed the resignator, but my mpg has gone down (I know lift and tires dont help) but I need a way to boost mpg with out voiding lifttime powertrain warrenty. I have a flowmaster 040. and yes I have the hemi.
on a side note, Damn I love my truck

 

Lol, not much you can do, without getting a programmer, and even that wont help you a lot.

 

your problem is the flowcrapper.. its sounds great don't get me wrong, the performance went to the negitive as soon as you put it on.

 

Oh yes, I neglected to see that.

Flowmasters are apparently more restrictive then the stock muffler.

 

Chambered design of the Flowmaster is not the greatest flowing muffler in the world, but your problem is LIFT, BIG TIRES & MORE AGGRESSIVE TREAD.

You want some semblance of gas mileage, then it's back down and soccer mom tires.

No combination of mods is even gonna come close to gaining back what you lost, besides the fact that you'll be spending more on the mods than the gas would cost you...

 

You won't be doing it with large tires, sry

 

That is the price for the tires and lift, either pay the price or go back to stock height and tires if MPGs matter that much to you.

With that said it may not be as bad as it seems... Did you have your speedo re-calibrated? Your speed will read low if not, which also means your miles are showing less than you are actually travelling.

 

Good point CarGuyOhio...I doubt that he did because it looks like he doesn't seem to have a tuner to do so. That would make the milage seem twice as bad as before...wow, lol!

 

ok my speedo is out by 4 and would a cai help?? also has anyone with a programer had any trouble with warrenty work, or can you completly delete it whem it goes in for work??? would a throtle spacer work and does they actually work?

 

At what speed because that doesn't seem like much for that tire change. The faster you go the more it will be off...more like 10 miles at 60 or so mph, just guessing. A CAI would help but I don't think a throttle body spacer would. I'd get a tuner of your choice with advise from someone here, they are both good but to each his own. You can easily set it back to factory settings and they can't be detected. Most important, I'd change the gear ratios (both front and back) to at least a 4.10 to compensate for the tire size...that would prob be your best bet if you can afford it..