[Jerry Bransford]

Originally Posted by Grewe02

Why does it not apply? Do you have both a 4 spd Auto and a 5 / 6 speed manual? Have you driven both?

It's such a well-known thing that I'm surprised you're even asking about it. The 4-speed auto needs lower gearing than the 3-speed auto and the 5/6 speed manuals for a given tire size. And I've driven all four tranny types and owned two of them with all kinds of ratios with both 33" and 35" tires.

[robncar]

Originally Posted by Grewe02

Why does it not apply? Do you have both a 4 spd Auto and a 5 / 6 speed manual? Have you driven both?

It does not apply because of the 4-speed auto having a 0.69 overdrive.

Here are the other 6-cylinder manuals and the associated overdrives:

AX-15 0.79; NV3550 0.78; NSG370 0.84.

Yes, I have had both and have driven both. I also, if you read the whole thread you'd know this, have a buddy that made a bad gearing choice and have experience from that as well. Not to mention countless other Jeeps that I've had experience with along the way. I currently daily drive a 4-speed auto.

I'm sorry if you felt my last post, or this one, was harsh. It's just that we've gone though a ton of posts on this topic and now you come in, say you didn't read the whole thing, and post 4.88's and 35's without consideration of the OP having a very tall overdrive.

[zband]

Thanks for the responses. For all that responded with 4.88's - I should say that my main concern is fuel economy (I live in Michigan its all flat) and I am concerned that the 17.53 mpg average I get now on the highway will inevitably drop with 4.88's. I was set on this gear until I spoke to one of the gear shops who stated, that for MPG: gear so that your running the lowest rpm in OD without kicking out of OD and without lugging. Unfortunately, running 65mph with 3.73's (1700 rpm) achieves this. I just dont see how 4.88 (2228 rpm) will save/ maintain my current MPG average. Sorry about the back and forth but I only want to do this once and I dont want to compromise mpg with gas now 3.70/gal.

[robncar]

Originally Posted by zband

Thanks for the responses. For all that responded with 4.88's - I should say that my main concern is fuel economy (I live in Michigan its all flat) and I am concerned that the 17.53 mpg average I get now on the highway will inevitably drop with 4.88's. I was set on this gear until I spoke to one of the gear shops who stated, that for MPG: gear so that your running the lowest rpm in OD without kicking out of OD and without lugging. Unfortunately, running 65mph with 3.73's (1700 rpm) achieves this. I just dont see how 4.88 (2228 rpm) will save/ maintain my current MPG average. Sorry about the back and forth but I only want to do this once and I dont want to compromise mpg with gas now 3.70/gal.

Ok, all I can say is "poop" to the gear shop that talked you out of this. I turn off the OD every day on the street because the RPM's are too low (lugging). Darn gear shops!

[chadsmeltzer]

Was it JCR you talked to?
I am getting 4.88's soon, and with the 35's I am hoping its not bad.
I don't know about you, but with 3.73 and 31's I am ALWAYS going in and out of OD on the little hills we have. I always have to get up to 63 at the bottom and will be near 50 at the top if I don't let OD go off.

robncar, how are the 4.88's with your 35's?

[robncar]

Originally Posted by chadsmeltzer

...robncar, how are the 4.88's with your 35's?

It's like night and day compared to the 3.73's. I do wish I had a D44 front so I could run 5.13's; I think they'd be perfect with the OD. With the 4.88's and the 4-speed auto I can take off like a drag car but turn off the OD on the street. 4.88's would be perfect with 33's and the 42RLE!

[zband]

what kind of mpgs are you getting on the highway?

[robncar]

Originally Posted by zband

what kind of mpgs are you getting on the highway?

On the highway, I get ~15MPG with a ton of armor, 35's, 4.88's, and a 5.5" lift with the 4-speed auto. In the city, on the street, it's closer to 13MPG. I think my MPG would be even better with 5.13's though.