Better fuel efficiency?

[XJumpmaster]

I have a 2000 XJ with intake and throttle body and 2 1/2" cat back exhaust. I have 4" of lift clearing 31" tires. I average about 14 mpg! I'm finding that this is below average mpg for an XJ. Is there something I can do to get better mileage? I just did the 90,000 mile service hoping that would help, but it did not. Any recommendations?

 

[Jeeptj98]

I have a 2000 XJ with intake and throttle body and 2 1/2" cat back exhaust. I have 4" of lift clearing 31" tires. I average about 14 mpg! I'm finding that this is below average mpg for an XJ. Is there something I can do to get better mileage? I just did the 90,000 mile service hoping that would help, but it did not. Any recommendations?

go back to your stock 235 tires. or all else fails sell the XJ and buy a Hybrid car.

 

[justdave]

I've heard switching to all electric fans helps.

 

[mbryson]

What gears? FWIW, I ran 32" tires with 4.10 gears and got about 18-19 mpg.


Edit: 18-19 was highway speed.....70ish

 

[Milner]

We never got over 14ish in town/16 ish hiway with 33's 4.10's and an auto

Just the basics....clean oil, clean air filter, proper tire pressure, plugs, cap, rotor, etc.

 

[DOSS]

We never got over 14ish in town/16 ish hiway with 33's 4.10's and an auto

Just the basics....clean oil, clean air filter, proper tire pressure, plugs, cap, rotor, etc.

my 01 XJ averages about 17... Was getting 14 before new plugs / Wires, Fuel filter (pain in the but job) and getting more air into the system (Made the most differance) K&N Filter and cut the airbox so it could suck air from more than just a 2X3 inch hole

 

[Brett]

I average about 16 in the city and around 20-21 on the freeway....that's with 33's and 3.73 gears.

 

[XJumpmaster]

OK, it seems the common recommendation is plugs and wires. Any particular brand? Also, i've heard of a cleaning kit for K&N, does this work?

 

[Brent]

one thing I've heard helps is to go easy on that skinny pettle, but like I said, I've heard that, can't bring myself to try it

 

[Devel]

Borg Warner makes a good wire especially the Nascar Selects, and i recomend putting in the Champion Truck Plug, they are the only plugs i ran in my cherokee and now my TJ :greg:

 

[Caleb]

OK, it seems the common recommendation is plugs and wires. Any particular brand? Also, i've heard of a cleaning kit for K&N, does this work?

I've always had good luck with the Autozone lifetime wires. The stock wires are usually about a 6.5mm wire (not positive on the newer rigs though) and the autozone wires were an 8mm wire...it was a noticeable difference in my 84 (or was it 85?) cherokee.

 

[mbryson]

Borg Warner makes a good wire especially the Nascar Selects, and i recomend putting in the Champion Truck Plug, they are the only plugs i ran in my cherokee and now my TJ :greg:

I've NEVER had good luck with Champion plugs (or Bosch for that matter). I've done better with AC or Autolite.

 

[XJumpmaster]

OK, I 've put in the Champion truck plugs and cleaned out the air filter. It sounds much healthier. I only got 12.5 mpg last tank so we'll see whats up!

 

[gijohn40]

I have a 91 xj and put one of these kits on it and got 17-19 MPG city 21-22 highway... just need to find the one for your year...

http://www.quadratec.com/products/17610_600.htm

this kit allows you to increase the spark plug gap so you get a larger spark to ignite the fuel better... I also installed a K&N filter and a throttle body spacer at the same time so it could have been the combination of all the above that helped....

 

[XJumpmaster]

That was kinda what I was thinking but in my 2000, there are no wires, it has coils. Its kinda cool actually! You can't screw up the order!(for us more technically challenged types!) LOL

 

[gijohn40]

well did you check all your coils? my expedition has a coil above each spark plug and one was bad but not to the point that it was not firing.... when I replaced it my mileage jumped up a few points!

If you have a timing light with the old clamp on ring you can go around and check each one to insure you at least getting a good spark.

 

[XJumpmaster]

If the plugs don't help, I will be replacing the coils. the dealer has em for $135 and every where else is like $150+ will see when this tank is gone....