gas mileage

[coon.hunter_21]

anybody know any tricks to give me some better gas mileage?? 87 comanche.4wd.4.0L 6cyl fuel injection.

I'm open to anything

[mvusse]

Greatest improvement can be achieved by changing your driving style.

 

http://www.hypermiling.com/

[tbrand]

What kind of mileage are you getting?

[coon.hunter_21]

I'm gettin about 15-17.depends on where I'm driving of coarse.i would say 17 mostly.

[Mongo]

Change your gearing, get fresh fuel injectors, redo your vacuum lines. Depending on your driving habits and axle ratio, that doesn't sound too bad.

[tbrand]

Check air pressure in your tires, take anything unnecessary out of the truck to save weight, etc. A general tune-up can help significantly as well.

[mnkyboy]

I would say your getting about average,that's about what my 4.0l xj gets.

The best my 2.5l has got was 18mpg,I don't even want to know what it gets now with the 33x12.50s

[86ComancheXNate]

What gear ratio is better for mileage? Right now I've got 4.10 with 31x10.5s with the 2.8 v6 I barely get 15 if I'm luckky normally around 11 or 12

[btm24]

4:10 is fine with 31's. Thats what I'm running and I think I'm getting around 12 :D

 

Brandon

[comanche12]

:agree: on most of info from ^^^^ posts

 

also my "advice" is put a real egg on gas pedal then drive around without break the egg :thumbsup:

[mvusse]

Also the 2.8 isn't known for mileage and makes just a hair more power than the 4 cylinder. Skinnier tires will also get better mileage. On top of that, good quality street tires will get better than the off brands, and any street (AT) tire will get better than offroad (MT) tires.

[Dechion]

Watching this one close and taking notes.

 

It's too damn cold out to be working on anything that does not absouletly need it, not to mention the snowpocalypse they are predicting for this week. On the other hand I am only getting about 12 Mpg on my 2wd / 4.0 Eliminator. I am planning on going through an working on that in the spring (along with everything esle that gets put off all winter)

 

Good info here on some things to start with.

[mvusse]

When my first 87 MJ was still stock, it would cruise 60mph on 235/75R15 tires (one size larger than the stock size on that truck) at 24mpg on flat ground. That was a 4.0 with an automatic transmission.

 

My new 87 MJ (2.5l 4 speed stick) I have only had for 15 hours, so no numbers yet.

[xjrev10]

gotta love the wintertime! I'm getting 8 with my 00 XJ on 31s driving back and forth to work! 242 has not come out of full-time since probably december 1.

[airspeed]

My 88 2.5, 3.55 gears and AX4 can get about ~18-20 in town and ~26 under ideal conditons. If I jump on I25 and try to stay up with the traffic moving 75-80 my mileage will drop to 16. At this high altitude 75-80 is pretty much full throttle, it reminds me of driving my 72 VW Bug.

[veritas4156]

Might wanna think about replacing the O2 sensor too. My 91 4.0L AX15 4wd was getting 19 city 23 highway and then my O2 sensor snapped in half (no idea how that happened, it was just hanging one day) and my fuel economy dropped down to around 11-15mpg. O2 sensors technically have a life of 75-125k miles depending on the manufacturer's recommendations. Not sure how much they effect the Renix motors, I've never had a Renix.

[Randy in Maine]

Well my 90 is still maintaining about 20 +/- 1 mpg (with 10% ethanol) when driven at 65 most of the time. 3.07 axle though 4x4.

[coon.hunter_21]

well gues i got to lookin when i was changin my oil and i seen i had some wires hangin.they went to a sensor on the side of the block.i figured it was the throttle body temp sensor.can that effect my mileage and is that it??its rite in front of the manifold on the block.its a 87 4.0L.