Optimal tire size and lift height for gas milage?

[Quills]

I am interested to find out with an XJ what is the best tire size and lift height for the best gas milage? I have the inline 6, 4 liter and stock front and rear axles. Currently I have a 6" lift and 33x12.5 tires. It is obvious that I get bad gas milage. Any thoughts...

 

[NWDave]

Stock, zero lift, with the lightest aluminim wheels you can find, with P215 tires, 5 speed tranny, with 3.07 differential gearing.

 

[xDUMPTRUCKx]

well the general consensus is 4.56 gearing with 33" tires is the biggest anyone should go if your into daily driving and milage and whatnot. You could fit 33s no problem with 4" lift.


you need to spend the money on gearing for you axles. it will cause undue wear on your transmission or clutch.


everyone is going to tell you that your not going to get great mileage out of a Cherokee with any sort of lift and tire combo.

they are correct.

 

[mk153smaw]

well the general consensus is 4.56 gearing with 33" tires is the biggest anyone should go if your into daily driving and milage and whatnot. You could fit 33s no problem with 4" lift.


you need to spend the money on gearing for you axles. it will cause undue wear on your transmission or clutch.


everyone is going to tell you that your not going to get great mileage out of a Cherokee with any sort of lift and tire combo.

they are correct.

X2 on 4.56's and 32's

20 Mpg is not out of the ballpark though. I avg 18 to 20 Mpg in the city and 20 to 22 on highway. I am on 32ish tires and 4.56 gears. I have a well maintained engine and driveline, which helps alot. I do not have anything on the roof which may cause drag. I have no interior save for the seats (less wieght up in the air). I have a big heavy rear end, the 14b is really heavy, which gets rid of the looseness the lighter rears have.

 

[Del00XJ]

Neh, no lift is better then anything. But who the hell wants to follow that one? How about 4.88 and 35's Mud Rovers?

 

[wolfpackjeeper]

you could just buy an old toyota camry and stop trying to make an XJ have good mileage. You will never get great mileage with one.

 

[Goatman]

I am interested to find out with an XJ what is the best tire size and lift height for the best gas milage? I have the inline 6, 4 liter and stock front and rear axles. Currently I have a 6" lift and 33x12.5 tires. It is obvious that I get bad gas milage. Any thoughts...

No lift and stock tires would be the best. However, if you have larger tires, having better diff gearing is key to better mileage. Stock gears with 33's isn't a good combination, 4.56's would get you better mileage.

 

[Dustin_XJ]

with the 4:56's can you still cruis the highway at 75 mph?

 

[xDUMPTRUCKx]

yepppers.

im sure many a person on this board commute with 33s and 4.56s.

with the 4:56's can you still cruis the highway at 75 mph?

 

[mk153smaw]

gearing, by theory, should never negate you from driving at cruise speeds. The reason you will gear is to correct ratio's of tire size and driveshaft revolutions to reduce torque's on the drive system. 4.56 and 33" ish tires act virtually the same as the stock setup. 44's on 5.88's do the same thing.

 

[NWDave]

"Reduce torque's on the drive system", that makes no sense! Even when geared correctly, the heavier tires, 33's or 44's, will have much more "torque's" on the drivetrain than lighter weight tires.

You gear up numerically when you lift and install bigger/heavier tires so your engine turns the same RPM as it did when you had smaller, lighter, stock sized tires. So the engine RPM's are up into its torque curve, and not lugging to pull hills and steep grades.

 

[trail rate this]

I drive 30 miles each way. I 33" BFG ATs 4.10 gears in a 98 XJ 4.0, AW4, 231, 4.5" lift. I checked my speed with a GPS and it's spot on with the spedo. I average 17.1 MPG (according to the overhead console). It's mainly hilly back roads and about 4 miles of interstate. MPG isn't great but I love my XJ, so I'll pay the little extra.

 

[proskier101]

i have 37"s and 5.13 and get about the same as my jeep did whjen it was stock...

 

[broqenjeep]

88,4L, AW4, 4dr, 30 x 9.50 cooper stt 16mpg no lift

 

[rocknxj]

you could just buy an old toyota camry and stop trying to make an XJ have good mileage. You will never get great mileage with one.

X2. I parked my XJ and am now driving a 2008 Honda Civic. I'm saving over $200 a month on my daily commute. Just think. After a year, I'll have saved enough money to buy one of those high priced hookers.

 

[Terrific]

Neh, no lift is better then anything. But who the hell wants to follow that one? How about 4.88 and 35's Mud Rovers?

Why Mud Rovers? If you're going to sacrifice mpg with a mud terrain, why not go with a higher quality tire than a Mud Rover?