Why is my gas mileage so bad

[cal]

Wow i get like 8 to the gallon.....of course i have a 3" budget and 32's with 3.55's. soon to have 4.10's

-PJ-

Go with 4.56's with 32's. 4.10's are not low enough.

With 4.56's, 32's and a good tune up (all good sensors and wiring) i was getting 22 mpg regular.

After going to 4.88's and 35's, I was running 18-20 regularly. I let the jeep sit a lot and mostly neglected it (other than wheeling) for a year and that dropped to 15 or 16, I'm figuring I have a bad sensor somewhere. Haven't fixed it because there's a stroker going in, will do it all with that motor.

 

[vortex]

See but i cannot get 4.56's outta any jeeps in the junk yards.

-PJ-

 

[cal]

See but i cannot get 4.56's outta any jeeps in the junk yards.

-PJ-

You aren't going to find 4.10's in anything strong enough to survive 32's, either.

Dana 35's and 32's is a reciple for a very very bad day.

(oh, and 84-90 4 cyl auto's had 4.56 gears factory).

 

[.40CalPatriot]

You aren't going to find 4.10's in anything strong enough to survive 32's, either.

Dana 35's and 32's is a reciple for a very very bad day.

(oh, and 84-90 4 cyl auto's had 4.56 gears factory).

I havent had any trouble with my 35 with 32's(yet) But I know it will be a problem someday.
Also I thought the 84-90's came with 4.10's not 4.56's?

 

[.40CalPatriot]

I havent had any trouble with my 35 with 32's(yet) But I know it will be a problem someday.
Also I thought the 84-90's came with 4.10's not 4.56's?

Ok just researched and say that they RARElY came with 4.56's, but for the majority it was 4.10's

 

[vortex]

Ok just researched and say that they RARElY came with 4.56's, but for the majority it was 4.10's[/quote

Ah ha that is what i was told.

-PJ-

 

[cal]

Its not that they 'rarely' came with 4.56, its that they RARELY came with a 4 cyl and an automatic.

=)

 

[cal]

I havent had any trouble with my 35 with 32's(yet) But I know it will be a problem someday.

I busted mine making a u-turn on gravel, stock gears and open diff. One wheel spun and then caught, BOOM.

Luckily I had a non c-clip dana 35 (on an 87), so I was able to strap it back to camp and have someone trailer me home. I knew it was a time bomb, already had an 8.25 with 4.56's and a locker sitting in the garage; had been waiting on a front axle to go with it.

Man, I almost miss having such small and inexpensive parts.

 

[badron]

If running rich check tail pipe for shoot, Check plugs to. Check for bad or missing O2s. A PO may have install O2 eliminators. A bad or altered MAP will eat the gas to. Often PO will tinker with it untill they end up with a mess. Then sell it off.

 

[time2getdirty]

what were you getting before the gear change? I have a 99 with 4.5" of lift 31" tires and stock 3.55 gears. I'm getting about 12 in town in 2wd on the warmer days of the years.

On another note does anyone know if the heater or electric fan in the winter will decrease gas mileage? I'm thinking about just unplugging my electric fan because its so damn cold. Someone told me that using your heater doesn't use any extra gas because it just draws the excess heat your engine is producing instead of wasting it.

i was getting 15-16... I have a heavy foot so i am proud of my heep...

 

[ipkyss]

I guess I am special. Dana 60s 37s and 5.38 gears. Still getting 15 on the highway

 

[Nevada City Sparky]

I just read in OEM tech that a gentleman had a loose connection on his temp sensor causing his Jeep to stay in open loop mode. Not allowing the engine to use the O2 sensor to adjust air fuel ratio. My 96 and my 94 average around 17-18 in the winter months. All backroads and 30% 4wd use.

That was me and I think I was wrong. A fellow member reminded me that the sensor on the head only works the gauge, not the FI system. Lookikng back on it, I HAVE been doing 4-5 mile commutes in the cold and the trip I took after the "fix" was a Sunday drive.

 

[Jeepm@n]

That was me and I think I was wrong. A fellow member reminded me that the sensor on the head only works the gauge, not the FI system. Lookikng back on it, I HAVE been doing 4-5 mile commutes in the cold and the trip I took after the "fix" was a Sunday drive.

Keep in mind there is a temp sensor for the gauge and for the computer on some XJ's I just don't know what years

 

[mudslinger4x4]

Wow i get like 8 to the gallon.....of course i have a 3" budget and 32's with 3.55's. soon to have 4.10's

-PJ-

how the hell are you only getting 8?! i'm running a 4.5", 32" MT's and 3.55's and get around 12 city and 14 highway. i try not to let it downshift at all. stay on the low end (~2000 rpms) and you'll be fine. if you need to speed up then you can jam it but other then that you'd be good. even doin 75 it's only at like 2500-3000.

now when i had my 33" boggers that was a different story. ~5 city and 7 highway. now that was fun...going to the gas station every 2 days