Shadetree

I just bought a '97 ZJ Limited / 5.2...Owner's manual says the tank is 23 gallons. Tne factory sticker that came with the owners records show an upgraded additional 7 gal gas tank...Has anyone seen this before? I'd rather not run the tank dry to find out....

ol"blue

I know on other Jeeps you can gain around five extra gallons by modifying/cutting the vent tube/hose inside the tank. Scroll down >->http://www.4x4wire.com/jeep/tech/fuel/15to20gal/
Maybe that's what they did on yours?

Shadetree

Back in '88 when I bought my 88 XJ it was only a 10 gal tank..The dealer told me if I'd buy it he'd switch it to a 20 gal..I asked how soon he could do it..He said it'd be done by the time we finished the paperwork..and it was..The mech said all he did was cut the filler tube. He said all tanks were the same size. Said if you ordered a larger tank that's what the factory did...Back then the info wasn't readily available (no internet) I'm hoping someone could tell me if they're still doing the same thing..and is it possible for me to have a 30 gallon tank..(23 + 7) ? I'm also suprised that my 5.2 is getting better mileage than my 4.0..Maybe the 200,000 mile difference on the odometer has something to do with it....

tiwvr1

My 94 5.2 gets better mileage then my friends 4.0. I got 220k on it, 4 inch lift, locker, 31 bfg km2, bumpers cut, stock motor and get 17.5 on highway and 13.5 around town.

Before lift I got almost 20 on highway and 14 around town. Assuming that the bigger engine needs less fuel to accomplish the same speed as a 4.0.

ol"blue

I can't say. But as far as mileage goes, I can tell you a personal fact. We own a an '04 WJ w/the 4.7L V8 that we bought new, and it now has 112,000+ miles. It has the 249 t-case, so it's AWD all the time. My brother has an '04 WJ w/the 4.0L I6 that only has 48,000 actual miles now. It has the 242 t-case so he uses 2WD most of the time. Last year on a trip from Mich. to Tenn., we both filled up at the same times and drove the whole trip together. Even though he used 2WD he only got 18 MPG while I got 19 MPG at 75-80 MPH the majority of the time. We were held up a while in a construction zone but that affected both of us for the same amount of time.
I guess the smaller engine had to work harder to keep up the speed, plus it just doesn't have the torque, so it has to rev higher to compensate.

jnicewan

I want to doubt this but its not impossible I guess. You dont have to run it out of fuel but let it get close maybe then fill it up. If you get a few gallons over 23 in the tank then maybe you have a 30gal tank. It just seems like there isnt enough extra room under there for another 7 gals, thats almost 1 and a half jerry cans of extra space needed.