Improving Jeep Cherokee/Grand Cherokee Gas Mileage

Comments

• 66phil Member Posts: 4

  May 2008

  Hi , I have a 97 , 5.2 v8, , so this may not apply exactly. I had 110,000 miles on it and I was running somwhat rough and showed it had an o2 sensor engine light problem. I replaced both o2 sensors with little improvment. What the problem was, the catylatic converter was pluged up, as well as the muffler. I replaced the converter with a performance Flow Thru type , and I bought a Thrush flow thru , street legal muffler, which has a 2 1/2 in outflow. This is larger than the factory 2 1/4 inch. I took it to a muffler shop and had them make a 2 1/2 inch pipe to extend this all the way out. The muffler shop at first didn't want to do it, it is eaisier for them to put on a ready made 2 1/4 inch pipe. It was $81 for the custom made one. I want to ad a few footnotes. I bought the converter on eBAy, it was about $85 with shipping. About half of what it costs at your local auto store. I bought the Thrush muffler at my local store, it was only $21.00. This is not the loud one, it is the street legal one, and it is very subtle and perhaps just slight louder than your standard stock type. I am sure you wouldn't be able to tell the difference if you heard it. I was able to remove the old muffler system and install the converter/ thrush myself. I did have to have the muffler shop finish the tail pipe, and they also welded everything together. My miliage went up Drastically. It is a little hard to gauge because my engine was running rough for maybe 6-8 months, but I have owned 2 19 96 Grand Cherokees and neither of them ever performed this well ? My in town miliage is up 4 mpg. Sometimes 5 mpg. Please keep in mind that my car was running rough, I also changed plugs and the air cleaner, but on my real time miliage guage on my headliner console, I will get readings sometimes of 32- 34 mpg when I am cursing at 50 mph. It never read that high ever, on either of my cars. Hope this helps someone. Phil Barry, Dunedin, Florida

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• tdose Member Posts: 3

  May 2008

  Thanks I will keep that in mind. I did find what is was looking for at rusty's offroading.com its a great site and i would tell everyone with a jeep if i could.

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• bscarcella Member Posts: 3

  April 2009

  My 2003 Jeep, at start up the RPM's climb to 2K, then very rough idle, RPM spikes. replaced Idle Air Control Valve, also new plugs. any suggestions

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• jeepia Member Posts: 1

  March 2010

  I have a 95 jeep grand cherokee laredo v-8 and it use a lot of gas. is there some things to do to give it better gas mileage I brought it used with very high mileage I like it, but the gas part. also I need to find a manual on it for the upkeep, ca not afford the new trucks. I know it need a lot of work to be that old and high mileage, but with tlc and new part could it be good. thanks

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• greyfox61 Member Posts: 1

  March 2010

  overheats after 20 min drive in temp exceeding 70 no problem in cooler weather.Replaced waterpump, pressure cap, radiator,hoses,fan clutch.It has 50/50 antifreeze.also left out the thermostat.It will cool down by running the heat w/fan on high.Problem started last yr after having a/c worked on,still don't work.

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• tuggajb Member Posts: 646

  March 2010

  sounds as if electric fans not working not good ides to run without thermostat drives computer control nuts

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• hot_jeep Member Posts: 1

  August 2012 edited August 2012

  Hey did you ever figure out what the problem is? My husband's jeep is a 90 cherokee laredo with inline 6 and it does the same thing. If we drive 30 miles in anything over about 75 degrees the car is almost to the red line. We've tried everything. Someone said to cut slots in the hood so that it gets more air but we didn't really want to cut the hood up. Another suggested replacing on of the fans with a bigger one that is electric.
  
  Any help/suggestions are greatly appreciated.

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