Just to give you a idea I have a 2011 2dr sport. Stock off showroom floor. Im getting on avg 19.5,20 mpgs(best was 21.6 worst was 18.3). Had her since mid April. Just cracked 4k. Thats about 90% highway miles. I can live with those numbers!!!
DONT DRINK AND POST
(I should follow my own advice once in awhile.)
Like rvrdvr said, depends on stock vs lifted, gears etc. I was surprised with the mileage i get. I got an 02 with an i6, 5 speed trans, 5" total lift, 35" tires and 4.56 gears and i get about 17 mpg..
It also depends on where you live, how much offroading you do, and if you tow anything. I live in central jersey and its pretty flat. If you live in a more mountainous area with more hills your mileage will be worse. Offroading also uses more gas. There are many factors.
i've had both in a tj. both were manual trans and both had 4.10 gearing. the 6cyl when i had 31s got about the same mileage as the 4cyl on 29s. it was around 16-17 mpg. if i were to ever get another 4cyl it would be a 2.5. i don't like the newer 2.4.
2003 Rubicon, 4.0L, 5SPD, Custom 4.75" lift, 33" MT Baja Claws
1999 SE, 2.5L, 5SPD, sold it
PM me for wheeling in and around Northern Illinois
Hi, hope you don't mind if I add my 2 cents,this is a pet project of mine. I have a good ex army buddy of mine,who has a beautiful TJ it has one of the shinnyest paint jobs I've seen. I don't knock that,how a person uses thier Jeep is thieer bussiness. I said "Ray, how come I don't see you out much any more?" Ray said this thing gets so bad gas mileage I can't afford to drive it that much,with gas over 4 bucks a gallon.thats bad for our hobby, the more Jeeps are seen,the better it is for us.makes people want them. as an old drag racer I know thier are things you can do to get what we call "free horsepower" now, don't get upset over that term. it means taking what you have,and making it run the best that it can,and getting the lost horsepower that is lost to ineffency. this equates to gas mileage,if you can keep your foot out of it.I'm not a big fan of stroker engines,or cammed engines that are for an every day driver.it makes the Jeep a single purpose vehical.a lot of Jeepers can't afford that.also I don't like mods that hurt the resale value either.any thing thats done,needs to be able to be undone,for resale.the same is true here as in the hot Rod resale venue.nobody wants some ones hot rod,thier ideas aren't the same as yours.they won't give you what you got in it.unless your name is Chip Foose.that said, this is no brag I'm getting 24 mpg out of an all most stock 2000 TJ with auto trans. this didn't happen over night. and no, I don't use drugs. I'm an ex aircraft mechanic. who was taught,that you don't do any thing untill you research it completly. first thing, you have to realize Chrysler had restrictions from the Feds (EPA ect) on how the vehical could be made. and the end result was a trade off, compromise, between the bean counters and the feds. the best thing available wasn't used due to cost.or noise restrictions. that includes low restriction air cleaners,they cost more and make too much noise.now I will go into what I've done to get the gas mileage I'm getting.and No! I don't sell any thing!. this works . first thing, I installed Bosch +4 platimum plugs, expensive yes, but I got a 1 mile improvement. then I installed Amsoil full synthetic fluids, trans, transfer case, power steering, engine,both differentials. now the next thing really po'd Amsoil. I found a product called Tufoil. it really works,look it up. the army is buying drums of it. they use it in the Abrums tank and the Bradly fighting vehical. I put the reccomended amount in the transfercase,both differentials,and the engine. when I changed the fluids to Amsoil. next was a Magnaflow cat converter.was told by an exhaust expert if you vehical is 10 years old your converter is half plugged. then a Banks monster exhaust system.finally a Ford Taurus electric engine fan. with a DC 2 relay controller. I cut the Ford schroud down to give me clearance. fabricated a schroud extension to mount the radiator overflow tank in the stock position. then I sealed the schroud to the radiator all the way around, I used a rubber seal that looks like a trunk seal,has a sticky strip . finally some black RTV to fill in where the seal couldn't reach.last thing was a really good looking stainless cold air intake system,that I got on eBay. I also got a heat schroud for it to keep the hot engine air away, eBay also. all of this together got me 24 mpg. the only thing left is a good tuned header that will offer good ground clearance. haven't found one yet for my TJ. still looking. the Jeep has gobs of power, and you have to train yourself to keep your foot out of it,or it's all for nothing. the wife loves it. says when she needs to,it can get out of the way in a hurry, LOL Tom
sorry, I left an important mod out. I've done so many, you can get lost. I installed a Trick Flow throttlebody spacer.these are the guys that make alum heads for NASCAR,and the NHRA.they know thier stuff. now older guys will remember from muscle car days, the factorys varied the height of intake manafolds, low rise,medium rise.high rise was for racing only,not intended for the street.it intended on the use.this goes back to free horsepower.and alowing the incoming air to develope more turblance,resulting in a better burn in the cylinders=more power from what you have.the Trick Flow piece is made from a phenolic material,insulating the throttlebody from the heat of the intake manafold. alowing the intake charge to be colder, there fore denser.making more power,with out changing the air fuel mixture.the most obvious thing I noticed,after install was,the Jeep ran smoother,throttle responce was quicker with out much pressure on the gas pedal.leaving me to belive I was on the right track. milage inproved 5 mpg. this spacer is heads over metal spacers,even though they have swirl groves machined into them.the heat insulation is the breaker of the barrier
sorry again, a mind is a terrible thing,when I get one it will be awful. I left out the alternator. I had to put in a Dodge Durango 160 amp alternator.because the Ford fan drew too many amps for the stock one.this again I got off eBay for 45 bucks used. the durango has a extra mounting point on the rear towards the engine. I could of sawed it off. but I left it on,incase it ever failed and I needed it for a trade in. it does make changing the first spark plug difficult,as you have to remove the alternator to get to it.this is a dirrect bolt in. and I changed my battery cables to 00 guage cables,got these from Summit racing, it is one cable used for mounting a battery in the trunk. has plenty of length and came with both connectors Neg and pos. I only had to go to Autozone for a connector for the starter end.got a copper one. it comes with the pos connector installed,so I put it on the battery fished it down,left proper slack marked it, put it in my vice and cut it with a hack saw. then I stripped it back about an inch and a half.installed the insulating boot that came with it.next was some large heat shrink tubing.installed the copper eyelet. I layed it on the anvil of my vice took my punch and put two good dimples in it to hold it on . cinched it up in my vice upside down. heated it up with the propane torch, and ran sodder down in to it. took the other end of the cable that was left after cutting it. it had the connection point eyelet on it. I installed it on the engine block in the ground position. left proper slack marked and cut it for the neg battery post. again stripped it back, installed neg battery clamp,put two dimples in it, put it up side down in vice ran sodder in it. all connections are soddered.you do not want to use crimp on sodderless connectors on a rough and tumble Jeep. they will fail you when you need them the most.(experiance and use heat shrink tubing to make the connection water tight. I also wrap my connections with friction tape,not electrical tape,after seeing electrical tape get brittle,unwrap and leave connections bare,I remembered friction tape,and why I hated it. it gets hard won't just unwrap,the factorys used it in the old days, it's more expensive.it just what I needed as my wiring skills are better now, and I don't need to get back in to fix what I screwed up. I've quit using electrical tape all together now. for the coup de grass I installed a 4 guage cable from the alternator to it's mounting point.it's like a stock battery cable. over kill maybe,but my Jeep allways starts,my battery will last longer,the engine fires immediately,the battery charge time is shorter.plus the coils get full voltage to fire the plugs,result better milage,happier spark plugs,they stay cleaner last longer. happy Jeeping hope this helps some one.