milage ?

4x4fever

New member
what kind of mpg should I expect from a 94 cherokee 4.0 h.o. a/t, stock gears, 2 in lift 31 in tires and air dam removed and how much will a roof rack drop it? I'm getting around 15 all around and think its lousy The engine has 170 g mi. on it but is in good shape It has stock intake an exaust an the cat was replaced about 30 g ago
 

WB9YZU

NAXJA Forum Supporter
You didn't mention how much crap you have in the roof rack, or whether it is the stock rack, or something with major frontage.

My 98' gets around 15 in town, 18 to 19 hwy when not towing. Set up is similar at 215K miles on original engine and stock intake and exhaust including stock airbox. Automatic, 5" of lift, 31" tires, and stock 3.55 gears. Bumpers are all home built so the airdam is long gone.

At one time I tried doing a home made K&N intake, it dropped my mileage by almost 3mpg in the hwy and dirtied up the intake tube, so I don't recommend it. I am not running a "stock muffler" I am running a welded turbo muffler because I got tired of all the cheap mufflers coming apart in 10K miles or less. I did not see any fuel economy difference, but it did get louder out back :(
 

4x4fever

New member
my bumpers are also homemade out of round tubing as is the roof rack
witch is not on yet. I'm doing the final welding on it this weekend.
Thanks for the anser as I seem to remember getting about 17 mph a couple of years ago. Is yours a h.o. and does that make a difference?
I would think it would and I had been thinking about a k&n
 

WB9YZU

NAXJA Forum Supporter
The HO designation was phased out. All OBDII 4.0L are by default "HO".

When I use the Jeep as an all around hauler, City/Hwy driving, I get more than 15, but less than 19.

Winter blend is at the stations by now, and that may be some of what you are seeing.

Do the usual gas mileage stuff. Tire inflation, plugs, cap & rotor. Use a lower viscosity oil like 10-30W regular oil for Summer, and maybe 5-30W for the Winter months. The owners manual has a nice chart in it regarding oil and temp.

Check your fan clutch. The fan should spin with a little resistance with the engine off, but not be locked. Viscous fans are a mileage killer when they go bad.
 

ttwitc9516

New member
I don't care what you have under the hood or how you drive it the best your'e going to get is around 18 mpg. I have a 2.5 5sp 4 wheel drive and I don't care how easy I take it I have never gotten any better than 18. I should have kept the 4.0 auto I had that got 17. Was much less of a pain in the A to drive.
 

jester4x4

New member
My '92 with a 3" lift, 31s and 243000 on the H.O. is only getting about 13 with a mix between city and hwy. I need to change the t-stat back to a 195 and see if that will help anything.
 

birchlakeXJ

New member
XJ's are bricks on wheels. Mileage can vary a bit from rig to rig depending on variables like engine condition, tuneup status, lifts, tires, winter/summer, etc. The best mileage I've ever seen on my stock 99 is 21 and that was twice in optimal highway only conditions. Most of the time I'm between 16-18, a little less in the winter.

Driving habits are a huge variable in what gas mileage you're going to get. You could take the same vehicle and have two people take turns driving it for a month. Guy #1 drives it like he stole it; Guy #2 eases and tips in the throttle gently and doesn't throttle up the skinny pedal and then brake down constantly. Guaranteed, their gas mileage will vary substantially (and as a bonus, Guy #2 will save on brake jobs). I'm not saying you should be a hypermiler; just saying that you have a lot of control of how often you're stopping to fill up.

I keep a small notebook in the glove box of every vehicle I own. Periodically (not every time) when I fill up with gas, I calculate mileage pump-to-pump and see where I'm at. If I see an alarming drop in my gas mileage based on what I had been getting for MPG, I start looking into possible explanations and causes.

You must do the math when calculating gas mileage. Trying to extrapolate your gas mileage from how many miles you drove since your last fill to where the gas gauge is at from your last fill is NOT ACCURATE! Do the division; takes all of 30 seconds.
 
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Davinator61

New member
The Manufacturer's Stated MPG for my '91 4.0L Laredo w/AT, PS, PB, AC, etc. is 14 in the city, 18 on the highway. Right now, she seems to be really close to that, if not dead on, as I've been very careful about maintenance, and have been using Amsoil's line of Full Synthetic Lubrication Products, since I first bought her in early February of '04, using their recommended intervals.
 
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