DougyFresh

When my XJ was lifted 3" with 235/75's, I averaged 18mpg on a trip to Louisville and that was counting the city driving during the week we were there. That was with me, my wife, our 4 year old, and our (at that time) 9 month old as well as 100+ pounds of tools, 50-75 pounds of clothes, 50 pound cooler, 50 pound spare, and probably 50 pounds of spare parts(didn't want to break down 50 miles from a parts store and not have parts).

Now with the same 3" lift, cut fenders, and 33's on stock gearing, it gets about 12 city and 18 highway (if I am driving, 10/15 if wife is driving) with nearly no cargo, just the family.

ZINGGG

Zactly

s346k

if mileage is what you want, I suggest leaving it stock. full on tune up, stock susp and 225 or smaller tires inflated to the correct psi.

my 97 is bone stock outside of cutting the face of the airbox and a 180 Tstat. I get 22-23 mpg mixed. I drive very little highway, maybe a total of 4 miles a day in my 30 mile round trip to work. I drive the speed limit and don't floor it off lights everywhere. I think if it saw more highway use that my mileage would increase.

I also removed the spare tire, tools etc and only keep a half tank of gas in it. the jeep weighed 3257 in that state.

it's possible to have a jeep and get decent mileage. not messing with it is the first step. maintenance is the second. I'm going to replace my cracked exhaust manifold with a header and replace the rest of the exhaust with high flow stuff. swapping to a 99 intake and some neon injectors as well. curious if that will improve or decrease my mileage. I'm a little hesitant to mess with it.

deputy112

Just checking in. It's been a few months. Anyway what are the best plugs for a 1999 6 cyl. Cherokee? Thanks

DieselDaze

I found if I leave it parked for a while I see exceptional results...

other then that, just drive it... after all its a jeep thang right??

Rogue4x4

The questions you ask can be found with a simple search...but since that is kinda hard, champion coppers

andrewmp6

Its a 4x4 thing they never get good gas mileage,A friends stock 4 banger stick tj gets like 14mpg.My brothers 01 f150 4x4 4.6 gets 15mpg highway 11mpg avg.In bone stock forum and drove right a xj can break 20mpg ish.

salad

+1 leaving it stock. Good mileage comes from low rolling resistance, good aerodynamics, low weight, keeping everything in tune, and knowing how to drive. XJs are OLD, most people don't appreciate that a "tuneup" pretty much includes "everything" now. After 20 years they're ALL wear items lol. Reducing parasitic loss by using a manual transmission and light synthetic oils in the entire drivetrain can also help: a typical automatic can see 25% of the power made disappear before it gets to the tires! Also make sure to take a dump before getting behind the wheel. Most people drive like they're permanently in race mode, especially in cities. Highways these days are actually too fast for an XJ, the economy peak is at like 55 MPH on flat land.

But you've got to ask yourself if it's really worth it. From a pure fuel economy standpoint, no. Get a Honda or an old oil burner. However if you plan on keeping your XJ another 10-20 years then replacing all the sensors and gadgetry along with other work like re-ringing pistons and new valve springs is all easily justifiable.

See, I have an evap leak right at the tank: Like everything else on this damn Jeep the line just rusted away! So mine uses fuel when it's off, too.

XJs got nothing on "classic" Jeeps for bad fuel economy lol. YJs and TJs are more brick than an XJ could ever aspire to be.

skife

14.85 cut 31 mud tires inflated to 45psi, decent amount of lift, 3.55 gears.

jeep and good milage don't go in the same sentance.

salad

31" mud tread inflated to 45? That must ride like a tractor lol