gas mileage

[punk kid]

what are you guys getting for gas mileage. I got a 99 xj with a CAI, a edlebrock header, and a a cat back exhaust. I have done a tune up on it and ran 44k though it but i am only getting 13mpg and i am on 31's. is this normal.

 

[MaxxXJ]

look at the bottom of this page for related pages... this topics been covered alot... but i'll play, in town i get 13 mpg with a 4" lift with 3.55 gears and 33x10.50 tires no cai or exhaust going down the freeway i've gotten 19 mpg but it wasnt flat ground it was going thru mountains roads

 

[Dr. Dyno]

'92 XJ, 4.6L "poor man's" stroker putting down 202rwhp/258rwtq, no lift, 27.4" street tires, stock 3.07's, AX15.
I get 16-17mpg in city driving, 20-21mpg highway (US gallons). Gained ~1mpg since doing '01 XJ intake swap.

 

[FlexdXJ]

'92 XJ, 4.6L "poor man's" stroker putting down 202rwhp/258rwtq, no lift, 27.4" street tires, stock 3.07's, AX15.
I get 16-17mpg in city driving, 20-21mpg highway (US gallons). Gained ~1mpg since doing '01 XJ intake swap.

You get that out of a stroker when others can't get that out of a turbo motor! Me thinks the turbo ones aren't done right! I hope to get that good of a number out of a stroker. Of course mine will be an AW4 for medical reasons.

 

[KillerCOM]

you probably haven't corrected your speedometer yet for the 31's. this throws off your odometer also...you need to get a tuner to recalibrate the speedo or something like Jet or Superlift's module

 

[FlexdXJ]

you probably haven't corrected your speedometer yet for the 31's. this throws off your odometer also...you need to get a tuner to recalibrate the speedo or something like Jet or Superlift's module

Or a speedo gear. You can also divide 31 by the OEM tire size then multiply the total miles by the number you get( i think its around 1.16 for a 31).

 

[MaxxXJ]

=) or buy a gps and carry it in the car...

 

[gravycrawler]

Try this,I used it on mine 00 xj w/ 410's w/265's. mph is right on

Tyres across
Diff ratio down
27"
28"
29"​

30"

(29.5)​

31"

(30.7)​

32"

(31.7)​

33"

(32.7)
34"
35"

(34.7)
36"
38"
40"
42"
44"
3:07
31
30
29
28
27
26
25
25
24
23
22
21
20
19
3:55
36
35
34
33
32
31
30
29
28
27
25
24
23
22
3:73
37
36
35
34
33
32
31
30
29
28
26
25
24
23
4:10
41
40
39
38
37
36
35
34
33
32
30
28
26
24
4:56
46
45
44
43
42
40
39
38
37
36
34
32
30
28
4:88
49
48
47
46
44
43
41
40
39
38
36
34
32
30​

 

[gravycrawler]

Sorry guys try this instead.great info on lots of xj upgrades including speedo gears
http://www.go.jeep-xj.info/

 

[HQuakers]

3" lift on 31s. 75% highway, 25% city. No engine mods or anything except a good tune up.
17-18mpg
With roof rack: 15mpg
With tire in roof rack: 14mpg