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Improving Fuel Economy (performace chips)

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Old 01-02-2009, 12:27 PM
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Default Improving Fuel Economy (performace chips)

I am new to the Cherokee, and am hoping to get better fuel economy. I installed a K&N air filter, and have seen an immediate decrease of 2 mpg. Hopefully the computer just needs to learn what to do with all the extra air.

Has anyone tried using a performance chip? Other ideas...perhaps new exhaust. I am not looking to break the bank. Thanks!!!!

16.5 mpg on hwy @ 65 mph.
Old 01-02-2009, 12:53 PM
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no chip out there that i have found for economy. but things to do is take out every thing u don't need in the car to reduce wight (ie. tools, spare, extra **** in trunk), reduce drag ( remove roof rack, put covering ova vents in grill, off road lights, deflector to direct air under your front axel. also can incresse air pressure
( but wears tires faster)


have u one a compleate tune up? plugs, fluid change (oil, dif, tranny, tc)
Old 01-02-2009, 01:06 PM
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My Jet chip helped some with power but not with fuel economy..I still get around 15/16 MPG
Old 01-02-2009, 01:20 PM
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that cuz jet = performance chip
Old 01-02-2009, 01:41 PM
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Originally Posted by xer0
have u one a compleate tune up? plugs, fluid change (oil, dif, tranny, tc)
It is still pretty new to me. Got it in November. The 60k maintenance is around the corner, so I plan on doing oil, fluid in transmission, transfer case, front and rear axle and the other stuff listed.

I just did a new air filter (old one was pretty clean but paper) and all the spark plugs. I had a misfire, checked them out and they were ready...

I probably will run the tires a little higher pressure, but they are currently at 35 psi.

When I first got it I got 19 mpg going down the freeway at 65.
Old 01-02-2009, 02:27 PM
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Originally Posted by wheelean
It is still pretty new to me. Got it in November. The 60k maintenance is around the corner, so I plan on doing oil, fluid in transmission, transfer case, front and rear axle and the other stuff listed.

I just did a new air filter (old one was pretty clean but paper) and all the spark plugs. I had a misfire, checked them out and they were ready...

I probably will run the tires a little higher pressure, but they are currently at 35 psi.

When I first got it I got 19 mpg going down the freeway at 65.

Your MPG sounds on par w/what I was getting in stock form, but don't expect all that much more from a brick on wheels
Old 01-02-2009, 03:36 PM
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what is your mpg now raypla
Old 01-02-2009, 03:41 PM
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Yeah I was hoping to get to that physiological barrier of 20 mpg. So I was totally bummed when it dropped to less than 17 after new plugs and a k&N filter. My buddy suggests just waiting and hoping the computer will learn, so we will see.
Old 01-02-2009, 04:13 PM
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Originally Posted by wheelean
Yeah I was hoping to get to that physiological barrier of 20 mpg. So I was totally bummed when it dropped to less than 17 after new plugs and a k&N filter. My buddy suggests just waiting and hoping the computer will learn, so we will see.

You can help the computer to relearn by unplugging your battery turning on the lights (as to completely draw the whole system) and letting it sit for 1/2 to an full hour, then when you reconnect the battery the computer will relearn the system. Did you replace your wires, cap and rotor along w/the new plugs? What kind of plugs?

Currently I get 14-15 on winter gas 90/10% city/highway. Don't forget the winter blend of gas usually gets a couple mpg less . Before I put the bigger tires on I got 24 mpg w/a full tank highway. Haven't come anywhere near that w/new tires, and thats w/corrected speedo. It is hard but the best way to get decent MPG's is to not go above 2000 RPM, that was yielding best results for me w/my AW4, but now that gas prices have come down I've been much more heavy w/the right pedal

If I was looking to get serious MPG I'd be looking into a small 4 banger DD, luckily I only live 10 mi from my work so I don't have to worry about it too much.
Old 01-02-2009, 04:39 PM
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Originally Posted by raypla
You can help the computer to relearn by unplugging your battery turning on the lights (as to completely draw the whole system) and letting it sit for 1/2 to an full hour, then when you reconnect the battery the computer will relearn the system. Did you replace your wires, cap and rotor along w/the new plugs? What kind of plugs?

Currently I get 14-15 on winter gas 90/10% city/highway. Don't forget the winter blend of gas usually gets a couple mpg less . Before I put the bigger tires on I got 24 mpg w/a full tank highway. Haven't come anywhere near that w/new tires, and thats w/corrected speedo. It is hard but the best way to get decent MPG's is to not go above 2000 RPM, that was yielding best results for me w/my AW4, but now that gas prices have come down I've been much more heavy w/the right pedal

If I was looking to get serious MPG I'd be looking into a small 4 banger DD, luckily I only live 10 mi from my work so I don't have to worry about it too much.
I just did the plugs. The caps were in a harness that was $180. Father-in-law is a mechanic 30 plus years experience. Both he and the auto parts guy said just use standard plugs. So nothing fancy.

Great suggestion on unplugging the battery. I will definitely need to do that.

Here in Oregon they cut the gas with Ethanol year round so the winter blend is here to stay. My next set of tires may have a better rolling resistance, but I need to have reasonable off road ability for hunting, camping, and shooting. Right now I have some 235 75 r15 Spector off brand tires that are a BFGoodwrich T/A tread pattern clone that the government (previous owner) put on.

Yeah the wife has a four banger, but I need tow...so I have the Jeep. Not the best mileage, but want to get the best I can out of what I have. Just supprised the my 4.0 L 01' Ranger did so much better (about 10-15% better)...but it had to go. Not a family friendly seating configuration.
Old 01-02-2009, 04:41 PM
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check my fuel saving tips VVV also, do a full tune up, all fluids, and O2sensors and plugs and wires
Old 01-02-2009, 05:37 PM
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cant do wires he has a 2001
Old 01-02-2009, 06:12 PM
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Guys we drive BRICKS on wheels not Hondas or toyotas, If you drive a Jeep you should expect poop mileage get used to it!!! And enjoy the freedom Jeep gives you!
Old 01-02-2009, 10:55 PM
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Originally Posted by Belto
check my fuel saving tips VVV also, do a full tune up, all fluids, and O2sensors and plugs and wires
Reading an old post of yours...did you ever swap out oil in the axles and see an improvement?
Old 01-02-2009, 11:11 PM
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Originally Posted by wheelean
Reading an old post of yours...did you ever swap out oil in the axles and see an improvement?
I did, and not really, buy you should do it, its pretty cheap to do, and well the oil inside if it hasnt been change never, it will smell real real bad so be careful not to splash it everywhere

that oil change is not a priority but it should be on your to do list


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