whats your gas mileage?

[87manche]

how the hell do you get 25 mpg on the freeway driving 70-75 mph with a 4.0L?
maybe your commute is downhill both ways?

it's actually not that hard.
Renix>HO for gas mileage.
I pulled 22 on the highway doing 70-75 with 1K pounds of weekend gear/front bumper/welder in the bed of the MJ.
1987 4.0 5spd, 3.73's and 31's.

 

[cal]

it's actually not that hard.
Renix>HO for gas mileage.
I pulled 22 on the highway doing 70-75 with 1K pounds of weekend gear/front bumper/welder in the bed of the MJ.
1987 4.0 5spd, 3.73's and 31's.

You forget to mention that the renix aw4's have a higher overdrive than the HO weenies get, too.

 

[53guy]

35's, 6" in the air, heavy as shit, 4.0, aw-4, 5.13's, 16.3mpg between 65-70mph.

oh yeah....and have the correct speedo....

 

[JNickel101]

Wondering how many people are calculating their MPG with an incorrect speedo gear....

 

[88xjchief]

I get abou 23 to 24 mpg in the city. Im rarely ever on the highway. Its all stock with 205k miles. 4.0, auto, 3.55.

 

[traitor5150]

18.7 highway 12.5-13.5 city CORRECT spedo Kuhmo 35 mt RE 5.5 Lift 4.88 gears Bored tb Pacesetter header stock everything else This was in my 1990 MJ shortbed 4.0 aw4... 65 higway.

 

[John90XJ]

OK, here's some really fresh info from Friday and Saturday.

Driving from Moab to Seattle, via the Bonneville Salt Flats.

Rig is a '90 XJ, 33x12.50 MTs at 30 psi, 4.0 with 258k miles running Delo 400 15-40 oil, AW4 with a tranny cooler and using Comfort position and shifting manually to 3rd when the RPMs dropped below 2k, 6.5 inches of lift, rig weighed 4975 pounds with passengers, 2.5% error factor on odometer confirmed over 100 mile stretch of milemarkers and GPS and the calculated mileage for the 982.2 miles of driving that had full fuel added at each stop was 17.63 mpg. Average speed over the distance was around 62 mph.

Most of this was at >4000 feet in altitude on 87-88 octane fuel. Stock Renix motor with early HO injectors, big K&N filter and 2.25" exhaust, with catco and large freeflow muffler. Temperatures ranged from 50* in the morning to about 95* in the afternoon.

The trip down was done at about 65 mph and the mileage was 17.03 mpg.

The weighted average over both directions was 17.34 mpg.

There were four major changes from our 2005 trip which netted a weighted average of 17.15 mpg:

Lift height is now higher by 2.5"
Roof rack is removed and all gear was inside
Overall weight increased by close to 200 pounds
Change in fuel injectors

The first and third items seem counter intuitive but the overall mileage did increase.

 

[87manche]

Wondering how many people are calculating their MPG with an incorrect speedo gear....

also true, 31's on a stock speedo gear will make your MPG seem poopy.
Mine was not corrected, but I've done the math, and checked it vs. a GPS, so I know how fast I was going.

 

[XJ858]

I know it has been said too many times already, but I have to say it again. THere is only 1 way to measure mpg, you zero your odometer, fill up a full tank of gas, drive around, refill your tank and note your miles. Then divide to find your mpg. The XJ computer just isnt accurate, and figuring you drove X number of miles on a tank so it must be X mpg is just wrong, and will give a bogus number every time, same goes for watching where the needle is on the indicator and guessing from there. I don't mean to point fingers or single anyone out, but come on, don't just thow a number out there without figuring it the right way.

 

[87manche]

I know it has been said too many times already, but I have to say it again. THere is only 1 way to measure mpg, you zero your odometer, fill up a full tank of gas, drive around, refill your tank and note your miles. Then divide to find your mpg. The XJ computer just isnt accurate, and figuring you drove X number of miles on a tank so it must be X mpg is just wrong, and will give a bogus number every time, same goes for watching where the needle is on the indicator and guessing from there. I don't mean to point fingers or single anyone out, but come on, don't just thow a number out there without figuring it the right way.

x2, my mileage was calculated based on the odometer reading and the fuel I put in the tank.
started with a full tank, ended with a full tank.
Althought pumps can shut off differently I figure that it should be accurate +- a gallon.

 

[RTicUL8]

Most I got out of an XJ = 26mpg (normal was more like 21).

It was a '93 stock XJ

2WD (less weight)
manual trans (less weight)
stock tires (less weight)
2 door no power widows or locks (less weight)
No a/c (less weight)
2.5L 4-banger (less weight)
About the only ammenity was a full size spare and an am/fm radio.

===

My current DD is a '00 sport loaded.
Getting about 17-18mpg.

===

 

[cal]

I know it has been said too many times already, but I have to say it again. THere is only 1 way to measure mpg, you zero your odometer, fill up a full tank of gas, drive around, refill your tank and note your miles. Then divide to find your mpg. The XJ computer just isnt accurate, and figuring you drove X number of miles on a tank so it must be X mpg is just wrong, and will give a bogus number every time, same goes for watching where the needle is on the indicator and guessing from there. I don't mean to point fingers or single anyone out, but come on, don't just thow a number out there without figuring it the right way.

I calculate mine via the trip meter for around town stuff, and use my GPS on the highway to verify it (trip meter/speedo are about 7% slow, so my numbers should be a little higher still).

 

[RaccoonJoe]

Was told the previous driver got 15 city/20 hwy, I could only get about 18.6 combined. Then had TPS problems, dropped MPG to somewhere btwn 12-15 hwy. I'm taking a road trip to VA this weekend, we'll see how the MPG goes this time

 

[Blue XJ]

14/15 in the city and 18/19 on the highway.

And is this really modified tech?

 

[markaboo929]

Check this out-I werk at a Hyundai dealer as a tech and across the street is an Infinity dealer-I just walked by an Infinity BIG suv-Nissan Armada in over price form-Guess what the fuel mileage sticker had on it????13 city 18 highway!!!! average!!!!! SO that being said I guess my 6.5 lifted WAY overwieghted in skid plated 88 XJ with 33x12.50 tires - 4.10 gears gets on an average-yes speedo is GPS acurate-17 MPG where ever I go hiway or city-does'nt matter cause it is a 5 speed and I always keep my RPM's at 2500 or more at all speeds - to me thats pretty dam good considering it is ran by a 88 renix computer-all be it an 03 grand cherokee 4.0!!!!party1: NV3550 trans to boot............

 

[SwissArmyJeep]

Oh the Value of the Guttless 2.5l.
I usually get 19/21 normal driving, 17/18 if I'm winding her out.
We just got back from a week long trip loaded with a big cooler, all our camping gear and recovery gear. I got some great highway numbers. Crusing at 60mph I pulled 25mpg, 75mph dropped it down to around the 20mpg range.
With 4:10, 31" tires in 5th grear, 75mph = about 3100 rpm, while the 60mph ran around 2500 rpm. :thumbup:

 

[lancey3]

16.2 mixed driving 3 inch lift

 

[Hugothegrunt]

That blows! I'm keeping around 20 combined with my stock 95 stick.

 

[Jeep9717]

If you guys havent figured it out already, you dont really use all 20 of those gallons in your tank. Its probably more like 18 or 19 if you dont run out of gas trying to figure it out. And the speedo gear is the only right way to figure it out if you have bigger tires, unless your just "estimating" like i do.

 

[cal]

If you guys havent figured it out already, you dont really use all 20 of those gallons in your tank. Its probably more like 18 or 19 if you dont run out of gas trying to figure it out. And the speedo gear is the only right way to figure it out if you have bigger tires, unless your just "estimating" like i do.

I wish I were as smart as you.