[prmike]

This is my first post and I'm new to this so bear with me.
I bought a 94 yj a few months back fairly cheap as it needed alot of work not to mention 225k miles. I replaced the I4 with one out of a 2000 tj with alot less miles it seems to run ok so I quickly put a small lift and tires on. its still gutless and thats expected out of a four banger but I've yet to see better than 13 mpg with either motor. is there something I should check or replace befor drawing up regret for selling my full size truck over economy woes.
dont get me wrong the Jeep is a fun little buggy I just had my heart set on high teens low 20s when I got a 2.5L

[Barrio]

i got a 2.5, i get about 12 mpg give or take

[prmike]

Originally Posted by Barrio

i got a 2.5, i get about 12 mpg give or take

That wasnt the simple fix answer I was shooting for. I guess oh well it sure is fun. it must be part of that: Just Empty Every Pocket thing

[Jeeples]

This is why many people stress getting the 4.0 over the 2.5. In real world driving conditions you will not notice much, if any, difference in fuel economy.

That being said, with 33's and around 5.5" total lift (and an Auto to boot), I still get better gas mileage than you do.

You may want to do a tune up, change your diff and trans fluids to a good synthetic, and also run a can of MOPAR Combustion Chamber Cleaner through the intake to help the engine operate a bit more efficient.

[BlackRhino]

I get about 14 mpg, but I know I also have a compression leak. I should think you'd at least get a couple better with a good running engine.

[goatboy]

You're in the normal range...I usually get 13-18 MPG, with 14.3 being the average...and I drive it pretty easy, the one thang that is really against me is my auto tranny...direct drive, ya see...at 70 MPG, I'm @ 3000 RPM

[BlackRhino]

Originally Posted by goatboy

ya see...at 70 MPG, I'm @ 3000 RPM

You get 70 MPG when you're at 3000 RPM?

[goatboy]

Originally Posted by BlackRhino

You get 70 MPG when you're at 3000 RPM?

Doh! I meant at 70 MPH, I'm @ 3000 RPM!!! Thanks for pointin' that out!!!

[bigh20rnr]

Well the last couple fill ups have been getting around 17mpg overall, have stock 3.55 gearing and 31 tires and I am pretty easy with the gas pedal. The jeep has recently had a full tune up and most of my driving is on rural roads with not a lot of stop and go driving. Good luck

Rick

[prmike]

so what kind of MPG are you 4.0 folks getting?

[kevin A Whitler]

My 4.0 with 31's averages 14-15 mpg..

[YJMan327]

I have a 2.5L with 33's and a four inch lift and get around 12-14 mpg. Before I got the lift, I had about 17. I'm gonna change some fluid (which have never been changed) and see if that helps.

[zeus87gn]

I have a carb'd 4.2l and average about 13-14mpg.
That's with stock 3.07 gearing on 30's and sometimes pulling a small trailer.

Jeeps are like driving a brick wall into the wind, but IMO something is wrong. I knew the power output of the 2.5 isn't much less than the stock 4.2, but the mileage should be better. I may be wrong, but I think you have put too much tire on there for your gears.

What size tires do you have?

[SinisterClaud]

you do the math... On Mondays i fill it up with $40 to $45 worth of gas, I drive a whole of 23 to 24 miles round trip to and from work... By Wednesday I am already thinking about getting gas... 1989 YJ with 33's... Not carburated I changed it to a 4.0 FI from a Cherroke... and my gas mileage still sucks....lol.. OH I live in NYC so gas is around $3.75 a gallon! weeeeee...lol I love my Jeep

[prmike]

Originally Posted by zeus87gn

I have a carb'd 4.2l and average about 13-14mpg.
That's with stock 3.07 gearing on 30's and sometimes pulling a small trailer.



What size tires do you have?

i'm running 32s and 4.10 gears but with the tires it steps it up to around 3.73 or so. I plan on going to 4.88s for the power problem but will have to hope on the mpg recovery