New O2 Sens, new plugs, new speedo gear still 13.5mpg, help.

C

Colorado S14

NAXJA Forum User

Location

Denver, CO

• Apr 8, 2011

• #1

Well, what next, I have been pretty dissapointed with the mileage from my 2000 XJ. I replaced the o2 sensor, the plugs, put in the correct speedo gear, did an oil change, and 2 tanks later I just filled up with a 13.9mpg. What do you guys think I need to look at next, it runs fine just get crap mileage, I only have a 2"BB and 30x9.5" tires.

 

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heyhar

NAXJA Forum User

Location

PA (near Poconos)

• Apr 8, 2011

• #2

There have been a few threads lately about mileage, and things to check. You don't mention a Coolant Temp Sensor. Change it. Or at least look for the threads, and figure out if you need one. You probably do. Test it and report back.

 

Johnnie Walker

Piece of Fish!

NAXJA Member

Location

WA state

• Apr 8, 2011

• #3

Plugged cat?

 

techno1154

NAXJA Member

NAXJA Member

Location

In the islands

• Apr 8, 2011

• #4

Colorado S14 said:

I only have a 2"BB and 30x9.5" tires.

Click to expand...

Did you calculate for the different size of tire over stock size? Did you re-gear the differential now that you increase the tire size? What is your driving style, a tortise or jack rabbit? How much extra weight do you carry in the XJ?

 

G

Gecko321

NAXJA Forum User

Location

Seneca, SC

• Apr 10, 2011

• #5

how long of trips do u make? a lot of small trips where the jeep and o2 sensor are not getting up to operating temperature will also cause lousy gas mileage. also are you using gas with ethanol in it? that also does affect gas mileage..

 

jmaxj

NAXJA Forum User

Location

in My shorts.

• Apr 10, 2011

• #6

your driving something with the aerodynamics of a brick, can't expect to much out of it.