Hello all,

I just bought a 95 Cherokee and for the most part it runs great, however, it gets about 160/170 miles to a tank of gas. Maybe I'm wrong, but this seems awful for a 4.0L with a 14-16 gallon tank (I'm not sure the exact size, but it's close to that). Tomorrow I'm going to do the plugs and wires and I've already replaced the air filter, but what else could be causing such terrible gas mileage? I can't imagine new plugs making that much of a difference. Is this just the price of driving a Cherokee or is there something else I'm over looking?

 

Hi, I have read in some posts that an oxygen sensor could be robbing the gas mileage, try doing a search and see what you come up with. Your XJ should have a 20 gallon tank BTW...Tj

 

You can try reading this post https://www.cherokeeforum.com/showth...ghlight=milage...Tj

 

Thanks again TJ, you've been a wealth of information. I did do a forum search but spelled "milage" as mileage so I didn't find much I'll be sure to check out the o2 sensor(s). Anyone know of hand if Jeeps generally have one or two? Also, for my last car (a 95 Toyota Corolla), the check engine light came on when the sensor went bad. I'll take it Jeeps don't do that?

 

There are lots of tune up type things you can do to you Jeep I-6 4.0: Sparkplugs, wires, Dist. cap and rotor, Clean TB to include IAC motor and adjust TPS. MAP sensor, O2 senor(s), Air filter, Fuel filter, Add fuel injector cleaner.
Here is something I just recently figured out as I have been trying everything to get my mileage back up after installing my front locker. My 91 4.0 HO likes to cruise on the highway at (2400-2500) RPM. Which is right around 70MPH with my gear and tire set up. The difference between me cruising at 70 MPH to 80 MPH is literally the difference between 21 MPG and 17 MPG. Crazy but true.

 

TrekkerJmm was referring to this. Click here >https://www.cherokeeforum.com/showth...ghlight=milage

 

Gas mileage is dependent on several things......

Tuned up properly
Tire pressure and alignment
Fuel delivery system efficiency ( are your injectors,throttle body, cylinders clean)
Mods, are you running oversized tires, ect
Gearing ( if you have lift or oversized tires)
Driving habits

Maintenance and driving habits are the biggest things you can do to make your vehicle as fuel efficient as possible. Remember though, Jeeps are for low torque, offroad applications and are as aerodynamic as a refrigerator box. Don't expect 30 mpg out of a cherokee.

 

No problem, glad I could help...Tj

 

EvilBlack XJ makes a darn logical point. It's hard to make a "high speed low drag" refrigerator on wheels....LOL....but, we try our best.

 

HAHA yeah I noticed that. LOL I had been driving a durango for a while and going back to an XJ I was like whaaa? seemed kinda high RPM's for 70-75. But from what I have looked at its about right...

 

[/QUOTE] Also, for my last car (a 95 Toyota Corolla), the check engine light came on when the sensor went bad. I'll take it Jeeps don't do that?[/QUOTE]

Actually jeeps do that as well, i have a 2000 cherokee with a bad sensor and the engine light is on i had it checked out at a shop near me and they said the only problem is a dirty sensor

 

Does the diesal model have a 20 gallon tank also...? I have a 1997 2.5 TD ltd se that i am picking up in the UK next week and driving to Poland...it would help my planning to know what size the fuel tank is on my Jeep....

 

X2 ^^^^ just did both of mine and it seemed to help. the C.E.L. hasnt come back either.

Try running injector cleaner. i did that along with a tune up (plugs, o2 sensors, air filter, oil, tire inflation) and i think my milage has gotten better.

Keep in mind.. you drive a vehicle that is about as aerodynamic as a phonebooth so you shouldnt be expectin the same milage as u got from your corola.

HTH

 

I know this thing isn't going to get anywhere near as good of mileage as my Corolla, but I just filled up last night and I'm getting about 12 miles to the gallon, OUCH. I just added the injector cleaner and I'm going to do the plugs/wires this weekend. Hopefully this helps. If not, on to the o2/map sensors. Thanks all for the advice!