Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here XJ (84-01)
All OEM related XJ specific tech. Examples, no start, general maintenance or anything that's stock.

Terrible Mpg even for a cherokee

Thread Tools
 
Search this Thread
 
Old Aug 21, 2010 | 11:05 PM
  #1  
bigboy813's Avatar
Thread Starter
Seasoned Member
 
Joined: Mar 2010
Posts: 497
Likes: 0
From: Santa Clarita,CA
Year: 2000 Sport
Model: Cherokee
Engine: I6 4.0
Default Terrible Mpg even for a cherokee

I don't see how other people are getting 13-15 mpg with a stock cherokee but i struggle to get an average of 9-10mpg around town things i have tried to get better mpg.

-Recently installed Bosch-Platinum+4
http://www.autozone.com/autozone/par...er=618321_0_0_

-Seafoam

-Gumout "All in one" Just put in tank today
http://www.oreillyauto.com/site/c/de...0407&ppt=C0126

-Lucas oil fuel injector cleaner
http://www.autozone.com/autozone/cat...oductId=369511

can anyone help me out on improving my mpg i know most of you are gonna you shouldn't expect good mpg yea i know but not 9-10 when its F--in stock

i get around 170-200 mile per trip.
Reply
Old Aug 21, 2010 | 11:25 PM
  #2  
bigboy813's Avatar
Thread Starter
Seasoned Member
 
Joined: Mar 2010
Posts: 497
Likes: 0
From: Santa Clarita,CA
Year: 2000 Sport
Model: Cherokee
Engine: I6 4.0
Default

bump
Reply
Old Aug 21, 2010 | 11:41 PM
  #3  
Rockstar_Tendencies's Avatar
Seasoned Member
 
Joined: May 2010
Posts: 354
Likes: 0
From: Hayden, ID
Year: 1989
Model: Cherokee
Engine: 4.0L I6 Renix
Default

Have you tried replacing the air filter? Upgrading your fuel injectors is suppose to get you a little more mph as well as hp. Removing the clutch style fan and replacing it with am electric would take more strain off the motor and should get you more mpg and hp I know there's performance gains from doing this.
Reply
Old Aug 21, 2010 | 11:46 PM
  #4  
trans_am7935's Avatar
CF Veteran
 
Joined: May 2009
Posts: 1,844
Likes: 4
From: Glen Burnie, MD
Year: 1994
Model: Cherokee
Engine: 4.0 H.O. K&N, Borla headers, custom down pipe, magnaflow hi-flo cat, flowmaster to turn down tip
Default

assuming that your motor is healthy and the bottom end is in good shape you should perform the following:

Priority 1:
New Fuel filter
Check timing with timing gun (set @ 11* advance)
new cap and rotor
Check ALL vacuum lines for leaks, especially near your intake manifold

Priority 2:
new plugs and wires set to proper gap
K&N air filter in stock airbox
aftermarket cat back (if desired, good for 1-2 MPG)

and last but not least...get some better fuel injectors. i pulled mine off an LS1 from a Trans Am and it gave me alone 2 MPG better! fuel economy is all about how the fuel atomizes in your cylinder and how hot it burns. a 195 t-stat will also give u best fuel economy due to proper ignition temp and going into closed loop mode. do these things first but main thing is the fuel filter under the drivers side right in front of the rear axle on the frame. good luck on your MPG mission, and for a reference, i get 13-15 MPG in my jeep. i run a 7" long arm lift with 35" mudders, 4.56 gears and duel lockers. so you should be getting better than me.
Reply
Old Aug 21, 2010 | 11:47 PM
  #5  
bigboy813's Avatar
Thread Starter
Seasoned Member
 
Joined: Mar 2010
Posts: 497
Likes: 0
From: Santa Clarita,CA
Year: 2000 Sport
Model: Cherokee
Engine: I6 4.0
Default

Checked it 4 months ago and it was pretty clean i know its to new to be clogged mabie i will check again
Reply
Old Aug 21, 2010 | 11:49 PM
  #6  
bigboy813's Avatar
Thread Starter
Seasoned Member
 
Joined: Mar 2010
Posts: 497
Likes: 0
From: Santa Clarita,CA
Year: 2000 Sport
Model: Cherokee
Engine: I6 4.0
Default

Originally Posted by trans_am7935
assuming that your motor is healthy and the bottom end is in good shape you should perform the following:

Priority 1:
New Fuel filter
Check timing with timing gun (set @ 11* advance)
new cap and rotor
Check ALL vacuum lines for leaks, especially near your intake manifold

Priority 2:
new plugs and wires set to proper gap
K&N air filter in stock airbox
aftermarket cat back (if desired, good for 1-2 MPG)

and last but not least...get some better fuel injectors. i pulled mine off an LS1 from a Trans Am and it gave me alone 2 MPG better! fuel economy is all about how the fuel atomizes in your cylinder and how hot it burns. a 195 t-stat will also give u best fuel economy due to proper ignition temp and going into closed loop mode. do these things first but main thing is the fuel filter under the drivers side right in front of the rear axle on the frame. good luck on your MPG mission, and for a reference, i get 13-15 MPG in my jeep. i run a 7" long arm lift with 35" mudders, 4.56 gears and duel lockers. so you should be getting better than me.
How can i fix leak even if i dont know if im leaking zip tie them ?
Reply
Old Aug 22, 2010 | 02:08 AM
  #7  
firstime00XJ's Avatar
Senior Member
 
Joined: Jan 2010
Posts: 712
Likes: 0
From: MI
Year: 2000
Model: Cherokee
Engine: 4.0 I6
Default

Originally Posted by trans_am7935
assuming that your motor is healthy and the bottom end is in good shape you should perform the following:

Priority 1:
New Fuel filter
Check timing with timing gun (set @ 11* advance)
new cap and rotor
Fuel filter is in the tank, non servicable. Timing is automatically adjusted by the computer and it doesn't have a cap and rotor if it's a stock MY2000 motor - Chrysler switched to coil on plug system. However, that is good advice if it would have applied. I have a 2000 Cherokee and I consistenly get 17 mpg. What are your driving habits like? If you like to stomp on the pedal, you're going to get poor gas mileage. I would check the air filter and spark plugs. Is your Jeep completely stock? Does it have a tow package? I've got 3.55 gears in my Jeep, being that it is bone stock.
Reply
Old Aug 22, 2010 | 03:27 AM
  #8  
bigboy813's Avatar
Thread Starter
Seasoned Member
 
Joined: Mar 2010
Posts: 497
Likes: 0
From: Santa Clarita,CA
Year: 2000 Sport
Model: Cherokee
Engine: I6 4.0
Default

Originally Posted by firstime00XJ
Fuel filter is in the tank, non servicable. Timing is automatically adjusted by the computer and it doesn't have a cap and rotor if it's a stock MY2000 motor - Chrysler switched to coil on plug system. However, that is good advice if it would have applied. I have a 2000 Cherokee and I consistenly get 17 mpg. What are your driving habits like? If you like to stomp on the pedal, you're going to get poor gas mileage. I would check the air filter and spark plugs. Is your Jeep completely stock? Does it have a tow package? I've got 3.55 gears in my Jeep, being that it is bone stock.

I dont really go above 2300 when acceleration and i do a lot of street driving
Reply
Old Aug 22, 2010 | 05:47 AM
  #9  
firstime00XJ's Avatar
Senior Member
 
Joined: Jan 2010
Posts: 712
Likes: 0
From: MI
Year: 2000
Model: Cherokee
Engine: 4.0 I6
Default

Make sure that you don't have a leaky head gasket. The 2000's have the infamous 0331 head casting that likes to warp and cause a leak. You may just want to have a compression test done. I'm sure that a lot of city driving doesn't help, however you shouldn't be getting 9-10 mpg. Like I said above, check air filter, looks like you've changed out plugs, although I'm not a fan of the Bosch Platinums.
Reply
Old Aug 22, 2010 | 06:25 AM
  #10  
bigboy813's Avatar
Thread Starter
Seasoned Member
 
Joined: Mar 2010
Posts: 497
Likes: 0
From: Santa Clarita,CA
Year: 2000 Sport
Model: Cherokee
Engine: I6 4.0
Default

Originally Posted by firstime00XJ
Make sure that you don't have a leaky head gasket. The 2000's have the infamous 0331 head casting that likes to warp and cause a leak. You may just want to have a compression test done. I'm sure that a lot of city driving doesn't help, however you shouldn't be getting 9-10 mpg. Like I said above, check air filter, looks like you've changed out plugs, although I'm not a fan of the Bosch Platinums.
hmm migh i add i may have a rear main seal leak plus my head gasket is leaking hmm mabie ill replace it
Reply
Old Aug 22, 2010 | 08:19 AM
  #11  
GrapeApe's Avatar
Junior Member
 
Joined: Apr 2010
Posts: 93
Likes: 0
From: St Louis
Year: 1995
Model: Cherokee
Engine: 4.0L
Default

Get rid of the crappy +4's. Go with OE plugs.
Reply
Old Aug 22, 2010 | 08:50 AM
  #12  
RoyalXJ's Avatar
CF Veteran
 
Joined: Jul 2009
Posts: 1,839
Likes: 7
From: West Deptford, NJ
Year: 97
Model: Cherokee
Engine: 4.0
Default

get rid of the crap +4 platinum plugs. go with a champion copper core
Reply
Old Aug 22, 2010 | 09:25 AM
  #13  
rich's Avatar
Registered Users
 
Joined: Sep 2009
Posts: 1,371
Likes: 4
From: morrisonville ny
Year: 2000 @ 1994 givin away
Model: Cherokee
Engine: 4.0
Default

Yeah you got something wrong city I get about 17-19 mpg and highway 20-22 mpg putting around off road I get less but not sure what it is there.
Reply
Old Aug 22, 2010 | 09:49 AM
  #14  
rich's Avatar
Registered Users
 
Joined: Sep 2009
Posts: 1,371
Likes: 4
From: morrisonville ny
Year: 2000 @ 1994 givin away
Model: Cherokee
Engine: 4.0
Default

Well lets see try champion plugs, did you replace the boots on the coil pack when you did the last plug change or replace at all? If not that can cause a weak spark, I run castrol 10w 30 synthtic mopar filter.195 t-stat, 3 core rad.factory fans and shrouds. 30 inch tires that are balanced right and 35 psi. All new filters and fluids. Also while a great idea to check the head I don't beleive it has anything to do with mpg well it at least had no effect on mine. Try all this if you want and see what happens.
Reply
Old Aug 22, 2010 | 06:49 PM
  #15  
firstime00XJ's Avatar
Senior Member
 
Joined: Jan 2010
Posts: 712
Likes: 0
From: MI
Year: 2000
Model: Cherokee
Engine: 4.0 I6
Default

Originally Posted by bigboy813
hmm migh i add i may have a rear main seal leak plus my head gasket is leaking hmm mabie ill replace it
Yeah the head gasket might be your culprit. When mine was leaking I was getting 10-11 mpg. Make sure that you have the head inspected for cracks; the last thing you want is to replace the gasket and have a cracked head. The RMS is an issue that should be addressed too if you've got the time/money and know-how.
Reply



All times are GMT -5. The time now is 08:58 AM.