gas mileage opinion

Ive been over concious of my mileage lately... and I think its alittle too low.

98 sport, I-6, auto, 3.55's.
mods: 4" lift, 31's (about 30.5) Mickey Thompson MTX, skids, load warrior rack with fairing, dynomax cat-back, new cat, mild bored t-body.
just got a full tune (plugs looked perfect), runs great, plenty of power.

Im getting 13 city, 15-17 highway, 15 mixed- tops.

Do you guys think that is average with these mods, or too low?

Im about to try removing the rack, and I have been playing with tire pressures, but that is for wear right now and hasnt seemed to effect mileage much. I have thought about replacing the Oxy sensor just as a maintance item, but cant afford to dump $$$ in the xj for no reason.

Thinking back, I probably only got 18'ish when it was stock..... so I guess it isnt too bad.

thanks in advance for any opinions, advice, or general comments!

I would guess that you are probably getting about the best milage you could get given the mods. I will say if you can get your O2 sensor changed do it. If that sensor is going bad then it may be causing you to run a little rich and in turn robbing you of a mile or so per gallon. Recently on my 89 XJ (auto trans and 128,000 mi. all stock) I went through the fuel and ignition system. I just replaced the fuel pump, filter, cleaned and flow tested all 6 injectors. Ended up having 3 of the 6 injectors rebuilt. New Oxygen sensor, new EGR sensors, plugs, plug wires, distributor, cap, rotor, and crank shaft position sensor. Granted this all cost me one hell of a pretty penny. But, I have gone from getting 18 - 19 MPG on the highway (40 mile commute all highway to work one way) to 21.5 MPG!

thanks!

couple other things... its got ~96,500 on it, corrected speedo.

Cherokee's have never been known for getting good gas mileage...especially modified ones. Learn to live with it

FWIW my 95 with 4.5 RE lift, 32's and 3.55 averages 12MPG in town and 17MPG on the highway.

I've never checked the mileage on mine, I don't really want to know, but it's not a daily driver either. My wife uses hers daily but only has about a 6 or 7 mile round trip to work.

I've got a 2000 with a 3.5" and 31's and that gas mileage sounds good to me. I have been getting 10 driving around town but that is a 5 mile trip to work and I haven't corrected my speedo.

ecrogers said:

I've got a 2000 with a 3.5" and 31's and that gas mileage sounds good to me. I have been getting 10 driving around town but that is a 5 mile trip to work and I haven't corrected my speedo.

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you haven't been getting 10 mpg.

You are going to get a WIDE range of answers to your question regarding what is normal, and I think the variation is due to more than just the differences in the way people account for milage. I have had two XJ's (1) a 1991 with 4.0 (OBDI), 5 spd and (2) a 1999 with a 4.6 stroker (OBDII), 5 spd. Both had the same 4.5 lift, same 32" tires, same 3.73 gears, and both had the proper speedo gear to adjust for the mods. The '91 never got better than 17 hwy, while the '99 always got between 18 and 21. I couldn't tell you the why's other than the extra oomph of the 4.6 might account for less skinny pedal.....

Anyways, YMWV is always true with XJ's. :sunshine:

xj-grin said:

You are going to get a WIDE range of answers to your question regarding what is normal, and I think the variation is due to more than just the differences in the way people account for milage.

Anyways, YMWV is always true with XJ's. :sunshine:

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I realize that, just looking for opinions, not definitive numbers. Thanks for your post! Your 99 is doing great!

BTW what is YMWV??? I suck at the 'IM talk'.....showing my age, I guess

fordtech said:

I realize that, just looking for opinions, not definitive numbers. Thanks for your post! Your 99 is doing great!

BTW what is YMWV??? I suck at the 'IM talk'.....showing my age, I guess

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its a fat finger typo -- YMMV = your milage may vary....

ZachMan said:

you haven't been getting 10 mpg.

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My speedo is within 10% of correct so maybe I am getting 10.9 MPG, who knows.

i get 15 to 16 in town and 19 to 20 highway. i have 4.5 lift 31 mt and no cat on a 91 but i have 3.75 gears stock. thats figuring every 70 miles im off 7 miles.