Oh ok. Well hopefully i can get mine up some if not oh well

 

What size tires are you running?

 

I've got a fairly stock XJ. 3" on 31's. I replaced the air filter with an OEM K&N filter and replaced the stock muffler with a Thrush glasspack. It's still got stock 3.55 gears (changing soon) and I can get 15-18 mpg in town, but I don't hot rod it.

 

My 4.5 and 32.5s gets about 17-18

 

Manual better than Auto for MPG

 

Don't forget to change your speedo gear to match the tire size you're running, otherwise your calculated mpg will be a little off.

 

How do you do that?

 

http://go.jeep-xj.info/HowtoSpeedoGears.htm

I just put 4.56s in finally (yes changed the speedo gear too). On first fill up, only got 12.8 MPGs. About a 1 MPG gain from stock gears. Joyous. I'm hoping it's because they're still getting broken in

 

Oh god yeah, with the cost of re-gear and the savings of an extra MPG it'd take 5 years to return that investment. Ouch.

 

I'm on a 3 inch with 31s and have gotten 12 to 15 mpg but that was on a fibered 02 sensor and 15 year old spark plugs. i expect to see more with my new sensor tho

 

What is the best sounding exhaust setup that's not too loud but nice and deep

 

I like my Magnaflow muffler and 2.5" tailpipe

 

Flowmaster Super 40

Here's the best setup for the $.

Check out 'mudfrog' on this forum, he runs this exhaust site
http://performance-curve.com/84-01ch...ailpipe-1.aspx

 

If you're like me and have a dead infection in your foot, it don't matter what you drive, your mileage will suck. As for exhaust, mine is a mandrel bent either 2.5" or 3" pipe, straight cat, no muffler. The PO had it on there, I love the sound, doesn't drone on the highway, but you know it's there when you accelerate

 

Here are some of my calculations from Fuelly.