Gas mileage
 

Hi guys , Just a basic question,
I have a 1998 Jeep Cherokee sport w 4.0 ltr .AT with 235,000 klms. Lt235x75x15 tires, Platinum plugs (which work really well) a K&N factory style filter ,new performance wires,cap and rotor. Use Lucas oil, 15w40 /Fram oil filter and I run injector cleaner every 4th tank on mid grade fuel.
Now here is the question: Is there anything else I can do to improve gas mileage? I get approx 325-370 klms to a tank :3gears: .
Is that good? I also heard of a guy who changed his trans to one that had an extra overdrive. but it didn't say if it was a jeep tranny of something else.
Any thoughts or ideas ? Thanks
P.S. I just read that someone changed injectors from a 2.5 Sebring and went from 12.5 mpg to 17.5?

Re: Gas mileage
 

Sometimes the injectors will just wear out over time, new ones will help a bit, not sure about an extra 5 mpg though maybe 1-2 I could believe. The extra capacity with a higher flowing injector will improve flow but the computer will still regulate them to the factory pressure unless you get the PCM flashed for the higher fuel flow and an adjustable pressure regulator installed.
I'm not sure on the range for the Cherokee, what size tank do you have in it?
Have you been keeping track of your mileage while using mid grade compared to regular? The 4.0 is designed to run on regular so not really sure how much of an increase you'll find.
Larger throttle bodies help a bit and so do the full high flow exuast systems.
One other thing some people have done is change the old 4.0 intake out for the higher flowing intake off a 99-04 GC.

Re: Gas mileage
 

this from another forum member,
"I recently purchased a 2001 sport with 179,000 on it, stock 3.55's and 31's. After a couple of steady 12.5 mpg tanks, I started looking for options. The easiest thing I could find was the Neon/Stratus Injector swap. I heard anything from 1-5 MPG in the reviews, and was intregued. I figured even if I could gain 1mpg steadily, that it was worth it for the money in the long run. I was careful to note how I drove before and after the swap, a mixture of mostly 45-55mph country cruising, and daily commuter stop and go.

I pulled the Injectors at the yard, (4 out of a 98 Stratus, and 4 out of a 00 Stratus...both with the 2.4l) They are all Chrysler part no. 04669938. Be careful with the Dodge Neons with the 2.0l as opposed to the 2.4. Just because they are the same year, and they have similar looking injectors, doesn't mean they are the same PN. They are too short.

Long story short, I got new O-rings, Soaked the injectors in Seafoam, Opened them up with a 9v battery and backflushed them with some shop air, and installed them. I decided to add some Seafoam to the fuel tank at the same time as I did the swap, due to some carbon deposits that I saw in the intake. I am normally not one for Magical Do-all potions for 10 bucks a bottle, but I read alot of people got better gas mileage running it through.

I just topped off the tank tonight after driving for 87 Miles, and it took 5.107 Gallons. That works out to roughly 17 MPG! From 12.5! That's a gain of 4.5 mpg.

I tried to treat this swap as objectively and scientifically as possible. I would say that I drove the last 87 miles as carefully as I drove the previous 400, maybe even more spirited. I did do a couple 0-70 digs right off the bat to see if there were any performance gains. I did notice a little bit more pull on the top end after about 3500...maybe. I wouldn't call it much of a horsepower/torque gain if any. Nor would I say I had noticeably better throttle response...as some have observed.

For my money, this is the best swap I have ever done. I will post more results as soon as I run a full tank through it."
__________________

Re: Gas mileage
 

This from another forum member,

"I recently purchased a 2001 sport with 179,000 on it, stock 3.55's and 31's. After a couple of steady 12.5 mpg tanks, I started looking for options. The easiest thing I could find was the Neon/Stratus Injector swap. I heard anything from 1-5 MPG in the reviews, and was intregued. I figured even if I could gain 1mpg steadily, that it was worth it for the money in the long run. I was careful to note how I drove before and after the swap, a mixture of mostly 45-55mph country cruising, and daily commuter stop and go.

I pulled the Injectors at the yard, (4 out of a 98 Stratus, and 4 out of a 00 Stratus...both with the 2.4l) They are all Chrysler part no. 04669938. Be careful with the Dodge Neons with the 2.0l as opposed to the 2.4. Just because they are the same year, and they have similar looking injectors, doesn't mean they are the same PN. They are too short.

Long story short, I got new O-rings, Soaked the injectors in Seafoam, Opened them up with a 9v battery and backflushed them with some shop air, and installed them. I decided to add some Seafoam to the fuel tank at the same time as I did the swap, due to some carbon deposits that I saw in the intake. I am normally not one for Magical Do-all potions for 10 bucks a bottle, but I read alot of people got better gas mileage running it through.

I just topped off the tank tonight after driving for 87 Miles, and it took 5.107 Gallons. That works out to roughly 17 MPG! From 12.5! That's a gain of 4.5 mpg.

I tried to treat this swap as objectively and scientifically as possible. I would say that I drove the last 87 miles as carefully as I drove the previous 400, maybe even more spirited. I did do a couple 0-70 digs right off the bat to see if there were any performance gains. I did notice a little bit more pull on the top end after about 3500...maybe. I wouldn't call it much of a horsepower/torque gain if any. Nor would I say I had noticeably better throttle response...as some have observed.

For my money, this is the best swap I have ever done. I will post more results as soon as I run a full tank through it."

Re: Gas mileage
 

Morning Rickster, interesting but I would wait to hear more on how it does mileage wise over time. Many things can effect the mileage of your Jeep. While in Fort McMurray I usually average 21mpg, down south around Blairmore I usually average 25mpg. Same driving style just a 2500' difference in altitude.
I think the idea is sound but over time I have a feeling that he's going to see that 4.5mpg gain dwindle down to 1-2mpg like I said before.

Re: Gas mileage
 

I really don't understand all the "I have to get better mpg" you bought a JEEP not a little foreign car with a 1.6 litre motor thats is a surprise it even can handle any bump in the roads without falling apart. I get between 15 and 19 mpg with 33/12.5r15 mud tires I know its got the air-o-dynamics of a brick on the road and don't expect to get 35 mpg. It cannot be improved and I live with it WHY? Because I like my JEEP and wouldn't drive anything else.. My Opinion

Re: Gas mileage
 

Install a vacuum gauge and learn to use it for the best economy.

Re: Gas mileage
 

Next up---the Hybrid Jeep. Not.