i got 22mpg in my 2wd xj last tank

 

xj's are aerodynamic as a cinder-block hahaha

 

Do you have a 242 transfer case? If you are running in full time 4WD most - all the time that could be why you are getting that poor of mileage. ( or really heavy feet )

 

My 2005 15 passenger (long wheel base) Savanna (1 ton) with the 6.0L V8 gets the same fuel economy as my '98 Cherokee. It has 65% more horsepower and torque and is pulling a vehicle almost twice the weight. It does not have variable valve timing and has similar multiport fuel injection as the 4.0L I6 from Jeep. I don't get too hot and bothered about the fuel economy of the Jeep but it does confuse me. Could something fundamentally be wrong with the 4.0L engine? It gets excellent horsepower and torque (per displacement) so I doubt it, but could something be off with valve timing versus stroke?

My engine is not running rich as the spark plugs come out clean - it might even be running lean as others have said, since the plugs have a slight yellow color near the tip. FYI I get 15-17mpg around town.

The engine does have very quick throttle response compared to my other cars. Could this alone account for wasted fuel as people's feet move slightly on the throttle while driving? I wonder if throttle response could be slowed - maybe an asymmetric pulley on the throttle body? I am just spouting on now so I'll shut up.

I'll look into having a different pulley for the throttle body machined to see how it changes things.

 

im open for a trade right now anything to get better gas mileage and somethng without mechanical problems i don't have too much money lol

 

Its called power to weight ratio...

 

Yea I have a 242 but never put it 4wd unless im stuck. I dont really have a heavy foot at all. But oh well thats the price I pay for having the ability to go anywhere I want.

 

I think that I am getting around 10mpg myself. Have not yet done a proper test, but it doesn't look good.
How the heck could it be that low? I would love and kinda need at least 15~18 mpg.
10mpg is just a freaking joke.

 

If you care about mileage you drive the wrong type of vehicle.

 

Yeah, but one expects at least what it is rated.
16/20 Old EPA
14/18 New EPA

Im getting roughly 10mpg. That is a pretty significant decrease compared to what it is rated, which means that their is something obviously wrong with my Jeep to get 10mpg when it is all stock minus the 225/75 tires, which doesn't change anything.

 

Aside from a tune up, the crank position sensor may be your problem. Lots of info on this if you do a search.

 

 

In my Blazer, which was the largest 4x4 I have ever owned. I got about 10 mpg driving city and highway and got 12.2 driving on the interstate at 65-70 which was as fast as I wanted to go with 40s, because of the road noise.
My Cherokee gets about 18-20 driving city and highway so I thought 10 mpg was really bad. I guess I'll find out about mileage after I do the lift, ring and pinion change and go to the 35-36 inch tires.

 

i drive 6 miles each way to work and in the cold of michigan i get like 8 miles to the gallon, maybe if my jeep warmed up before i shut it off i would get better mpg

 

19.3 mpg stock 225 tire four wheel drive 4.0. mostly highway. It was 16.2 before i got new set of NGK spark plugs and changed rear diff. fluid.