9mpg? :(
I know cherokees aint priuses, but why am I getting 9mpg!?
Also whrn I have the ac going and the auto tranny downshifts for power, the belt (i think a.c) makes a LOUD whistle? Kinda emabarassing/annoying
Also whrn I have the ac going and the auto tranny downshifts for power, the belt (i think a.c) makes a LOUD whistle? Kinda emabarassing/annoying
CF Veteran
Joined: Nov 2008
Posts: 1,021
Likes: 3
From: mass
Year: 1992
Model: Cherokee
Engine: 4.0 high output
that doesn't sound right. 9mpg is low.
i have 3" lift, 31s, heavy bumper, winch, roof rack and lights and I'm getting 15/19
I was still getting 12/14 before I did a "full" tune up. spark plugs, cap, rotor, wires, new o2 censor, apn header to replace my cracked one, dynomax cat back exaust, 703 injectors, fuel filter, cleaned intake manifold and throttle body, made a cowl air intake, and new air filter
i have 3" lift, 31s, heavy bumper, winch, roof rack and lights and I'm getting 15/19
I was still getting 12/14 before I did a "full" tune up. spark plugs, cap, rotor, wires, new o2 censor, apn header to replace my cracked one, dynomax cat back exaust, 703 injectors, fuel filter, cleaned intake manifold and throttle body, made a cowl air intake, and new air filter
Originally Posted by xjheep92
that doesn't sound right. 9mpg is low.
i have 3" lift, 31s, heavy bumper, winch, roof rack and lights and I'm getting 15/19
I was still getting 12/14 before I did a "full" tune up. spark plugs, cap, rotor, wires, new o2 censor, apn header to replace my cracked one, dynomax cat back exaust, 703 injectors, fuel filter, cleaned intake manifold and throttle body, made a cowl air intake, and new air filter
i have 3" lift, 31s, heavy bumper, winch, roof rack and lights and I'm getting 15/19
I was still getting 12/14 before I did a "full" tune up. spark plugs, cap, rotor, wires, new o2 censor, apn header to replace my cracked one, dynomax cat back exaust, 703 injectors, fuel filter, cleaned intake manifold and throttle body, made a cowl air intake, and new air filter
Sounds to me like your A/C pump is binding up and close to not tuning at all. This would create a lot of drag on your motor and cause it to work much harder then it should causing your poor mileage.
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CF Veteran
Joined: Nov 2008
Posts: 1,021
Likes: 3
From: mass
Year: 1992
Model: Cherokee
Engine: 4.0 high output
Originally Posted by roninofako
When you did your injectors, did you flash the computer? Made a world of difference on my swap...
CF Veteran
Joined: Feb 2010
Posts: 5,420
Likes: 0
From: Soddy Daisy TN
Year: 97
Model: Cherokee
Engine: 4.0L
Senior Member
Joined: Aug 2011
Posts: 710
Likes: 0
From: Santa Rosa, CA
Year: 1996
Model: Cherokee
Engine: 4.0
96 xj manual 5speed
4.5 roughcountry long arm
33s with 4.56 locked diffs front and rear.
I get 20MPG on highway at 65mph.
used to get 12. thought noo way...
got some marvels mystery oil put it in my gas tank and my MPG dropped to 8 on that tank. ( cuz it knocked more sediment thru)
then I replaced my fuel filter and ran some sea foam thru my intake and its now 20mpg
and man oh man that fuel filter had alot of sediment in it.
4.5 roughcountry long arm
33s with 4.56 locked diffs front and rear.
I get 20MPG on highway at 65mph.
used to get 12. thought noo way...
got some marvels mystery oil put it in my gas tank and my MPG dropped to 8 on that tank. ( cuz it knocked more sediment thru)
then I replaced my fuel filter and ran some sea foam thru my intake and its now 20mpg

and man oh man that fuel filter had alot of sediment in it.
CF Veteran
Joined: Sep 2010
Posts: 1,992
Likes: 0
From: West Bloomfield,MI
Year: 1996
Model: Cherokee
Engine: 4.0L, CAI, Edelbrock Breather, Optima Yellowtop
I'm getting 14 mpg with a 3 inch lift, 31s, Flowmaster 40, Roof rack, Roof mounted spare, Jerry can, Shovel, lights, Solid steel prerunner bumper, etc.
I haven't really done a "full" tune up though. I've just cleaned my throttle body, Replaced the spark plugs with champion coppers, Replaced the plug wires with MSD 8mm's, and seafoamed it. I still need to replace my O2 sensors, do my neon injector swap (I have the injectors, but don't have the time to swap yet), put my snorkel in, and get a bored TB.
I haven't really done a "full" tune up though. I've just cleaned my throttle body, Replaced the spark plugs with champion coppers, Replaced the plug wires with MSD 8mm's, and seafoamed it. I still need to replace my O2 sensors, do my neon injector swap (I have the injectors, but don't have the time to swap yet), put my snorkel in, and get a bored TB.
Newbie
Joined: Mar 2011
Posts: 12
Likes: 0
From: Prince Edward Island, Canada
Year: 1999
Model: Cherokee
Engine: 4.0L
I'm getting 14 mpg with a 3 inch lift, 31s, Flowmaster 40, Roof rack, Roof mounted spare, Jerry can, Shovel, lights, Solid steel prerunner bumper, etc.
I haven't really done a "full" tune up though. I've just cleaned my throttle body, Replaced the spark plugs with champion coppers, Replaced the plug wires with MSD 8mm's, and seafoamed it. I still need to replace my O2 sensors, do my neon injector swap (I have the injectors, but don't have the time to swap yet), put my snorkel in, and get a bored TB.
I haven't really done a "full" tune up though. I've just cleaned my throttle body, Replaced the spark plugs with champion coppers, Replaced the plug wires with MSD 8mm's, and seafoamed it. I still need to replace my O2 sensors, do my neon injector swap (I have the injectors, but don't have the time to swap yet), put my snorkel in, and get a bored TB.
Is there a better o2 sensor to buy? Or just go with a typical after market one?
I'm waiting for my Rough Country 3" lift and I got 31's on rims out back for my XJ and just wondering what all I can do to keep the mpg decent. I need to replace my manifold (cracked) and I was looking at an ebay header, worth while?
Any other tips I'd love to hear it.







