TegTegxj90

i have a 1990 jeep cherokee 4.0L,auto trans and stock everything. how many miles should i be getting per tank of gas because so far im getting just shy of 200 and it just seems like i should be getting a little more seeing as my chevy s10 with a 4.3 is getting closer to 275-300. also what should my average mpg be?

kjc

'93 JGC Laredo.. I average just under 400 miles per tank (23 gal tank) The last time I bothered to keep accurate track of it, my mpgs were just under 15mpg. During the test, I was driving like a li'l old lady to maximize When I drive normally, probably around 12mpg. How are you keeping track?

Turbo X_J

You are comparing apples to oranges.

loligator

In my 95 I got about 200-220 after I did the fuel injector swap but when it was stock I got about 180-200. I just picked up a 96 XJ that's stock and I appear to be getting about 200. Only on my third tank of gas but I believe about 200 miles to a tank is correct. What's that equate to, about 15-16 mpg?

kgm

Give it a full tune up, you should be able to get more. All fluids, plugs, wires, o2 sensors, etc. It'll pay for itself after a few months of better mileage.

TegTegxj90

i rest my trip when i fuel up and then let it get to about half tank then fill it back up and do the math between how many miles to how much fuel it used.

kgm

I get ~18mpg right now per tank if I get on the highway sometimes. If I'm just sputtering around town in the cold, I only get like 13. I ride my bike in town cause it doesn't make sense to blow gas on corner store runs. It ends up being 300-325 per tank but I usually fill it up at half tank to avoid stressing the old fuel pump.

salad

Start with a FULL tune up including air filter, proper weight oil, good oil filter, copper spark plugs, wires, distributor rotor and cap with brass contacts, and new O2 sensor. Make sure vacuum lines under the hood are intact and connected. Make sure you are running the right tire pressure (around 32 PSI)

Also, 1987-1990 require a bit of special love. This link has fixes to most common problems with the Renix generation https://www.cherokeeforum.com/f51/cr...x-tips-153657/ A lot of those will improve performance, as well.

Also... is the transmission switch in POWER or COMFORT mode? Comfort uses more gas

TegTegxj90

to be honest i dont believe the trans switch even works, when i click it either way nothing happens to the rpm's, it doesnt shift different or ne thing. is that how its suppose to be?

Ol' Green

I have a stock 98' Cherokee and Im getting about 17 MPG in the city.

loligator

to clarify, i did the math and i get about 15mpg average. i sit in a decent amount of traffic to and from work. the 180-200 miles per tank is letting it get to a quarter before I fill. i just did a full tune up so unless i did something wrong, I think that's all there is to get out of these 4.0L motors.

kgm

Yeah anything other than highway and they will eat gas. I try to avoid using mine for around town driving if I can. I get 8mpg sometime when its really cold out and I'm only short tripping it. Woof!

TegTegxj90

What are u guys running for rpms on the highway at 65-70? Im at about 2500 rpms at 65 and it just sounds a little loud

Fivefifty%

I have a 1995 XJ Sport 4.0 HO motor with 3 1/2 inch RC lift on 235/75/15's with ford injector swap and I get 300 to 320 per tank and that's from full till the gas light comes on. I have gotten as much as 350 a tank on 93 octane. And I thought that was bad cause my WJ got 400+

Fivefifty%

At 70 RPM I'm at 2200 at 55 RPM am at about 1800