Automatic causing bad gas mileage..what to do?

I have a '93 Cherokee, 4.0L AW4 with 4.5" lift with 33's. I live in a smaller town where the speed limit is mostly 35. The problem i'm having is that the stupid AW4 seems intent on getting to 4th gear as quickly as possible.

I've noticed that the engine seems happiest and most efficient in the 2000-2500rpm range (is that right?), but the AW4 loves to lug around town at 1400rpms where the slightest hill will cause the motor to groan. Not surprisingly i'm getting ~14mpg around town (though i do get 18-19mpg out on the road).

I considered doing a manual swap because i generally prefer manuals anyways, but i also found radesigns.com and some DIY on manually controlling the automatic. One thing they don't mention is how the lockup is controlled (other than if i want to add a manual switch).

It also seems like it's more intended for offroad-only, whereas i'm looking at this for gas mileage and because general irritation with my automatic. I also have a lot of steep hills where i like to keep it in 2nd and occasionally get the jarring 1st gear jump.

Any feedback for my use case? This is not a daily driver but I would want it to be something my wife could drive if need be. Ideally it would be like a manual without a clutch!

leave it in 3rd. i usually drop mine down to 3 if i stay below 55 on twisty roads for the quicker engine response and a little more engine braking.

drop it to 3rd x2

and.... 14 aint all that bad in town, pretty normal considering tire size...

I'm with this "Barney" on this one. The only thing would suck is if you have a full-time locker in the rear. The automatic smoothes out decelaration from my Detroit.

Are your gears/ rear axle set-up stock?

Your getting what jeep rated it at stock, I highly doubt a manual trans will make it any better.

Actually 14 city isn't bad. 18-19 hwy isn't bad either.

Be glad you don't own an 01'.

As so shifting...
I am going to assume you re-did your speedo gear and the trans comp knows how fast you are really going

If you have, then I might be interested to see what changing the TV adjustment would do for your shift points. On older, non-computerized Mopars, it changed the shift points slightly. Not sure what it would do with a Electronically actuated trans.

whitexj98 said:

Your getting what jeep rated it at stock, I highly doubt a manual trans will make it any better.

Click to expand...

i know a manual wont make things any better. lol.

I forgot to mention i have 4.56's and my speedo is corrected.
Other than that, well that's both good news and bad news! I really hate getting 14mpg but i guess i can't have everything.

I just ran a quick errand and tried it in 3rd and it does seem better. It stayed around 14-1500 but it lug as badly as it does in 4th.

Maybe it's just time to get a commuter....

Your mpg isn't bad at all. I get ~13 on 6" and (temporary) 31s.

Remember, winter fuel has more ethanol in it, which usually causes worse mileage. But, Even with my short amount on the highway for daily driving I average about 14-16. Renix 242ci/AW4/231 31's w/ 4.10s More or all highway I usually pull high teens if not low 20s.
But if you want better "city" mpg. A beater is your best bet.

adjust the TV cable at the throttle body

Tv cable doesn't do much/anything. Mine is locked out all the way for a little harder shift and full line pressure.

I was going to ask if you were geared yet, but you said you were. Those are pretty good numbers for a lifted jeep on 33's. You have to remember a couple things, 1) you present more frontal area because you're lifted so your un aerodynamic brick is even less aerodynamic. 2) your 33" tires have more contact area and more rolling resistance, so that's going to impact mileage. 3) 33" tires just weigh more, so it's more mass to start moving and more mass to stop. Considering your numbers, 14mpg is pretty decent mileage for what it is. Most of us eventually just buy an econobox for commuting and only take the jeep out for fun.


Mark

A bad TPS can affect shift points.

The tV cable adjustment is good to do as a matter of course, as those cables stretch. Takes 30 seconds to do.

93 doesn't have the Power/Comfort switch does it?

14 city /19 freeway is great . I get around 14 freeway if Im lucky with 36s/4.88s/lots of weight. The best I ever got was 17mpg with 33s and stock gears on the freeway.