It's strange....I started a similar thread a few days ago but when I went back the next day to check responses it was gone!

So I' just ordered an '08 Sahara auto 4 dr and had to settle for the 3.73s. I plan on running 35's (34.6 actually) and I know that people recommend at least 4.10s but it seems that everyone talks about highway speeds. My situation is very different so I want to get some info for my particular scenario. First off, I moved down to Mazatlan, Mexico last year and it's a fairly small tourist town with no highway in town. I'd say 95% of my driving is along the beach in town (congested) so I rarely go over 30. A couple of times a month it's my turn to drive north on the highway to some secret surf spots but they are only 20-30 miles on the highway. Then maybe twice a year we drive back to AZ and CA to visit family where we'll put on a few thousand miles per trip. On these trips I'll throw the stock 32's back on for better gas mileage and to save my good tires.

So, given that I'm just driving around town will I be fine with 3.73 gearing? Doing the math (and it's likely I screwed this up), it looks like going from the stock 32's to 34.6" tires is about an 8% increase in diameter while going from previous 3.21 gearing up to 3.73 is about a 16% increase. I realize people complained about the 3.21s but it seems like I'd be ahead of the game with the 3.73. Jumping up to 4.10s from 3.73 appears to only be another 10% increase in gearing (not sure if it works that way mathmatically). I also have read a few peoples comments that 4.10 with 37" tires weren't as bad as they thought it was going to be so I was thinking that would't be much different than 3.73 with 35s (34.6").

So what do you guys think given my scenario? I know there are guys out there talking about running 5.13 or 5.38 gearing with 35's but they are also talking about doing 90 mph (about 3 times the speed I'll average). The other thing to consider is that a good chunk of my total mileage and almost all of my highway miles will be with 32" stock tires on so going to 4.88 or 5.13 wouldn't be very good right? If it's necessary I'll change my gearing but I just wonder if it will be that big a deal around town.

Thanks!

 

Put it this way.... I have the 4.10 with stock 18" wheels and the automatic. Most of my driving is around town where the speed limits very from 30-45 on average. I do highway trips at least once during a tank full. At 40mph my rpm's are right at 1100. If I had the 6speed I probably just keep it in 4th or 5th gear and be just fine with it. But having the Auto I have no choice. I would have already bought a 4.88 if I wasn't planning on larger tires eventually. A higher gear would be alot more drivable in my opinion and that's with just the stock 18".

 

35's and 3.73 will suck bad. You will have no power and you will loose 6th gear.

 

Absolutely.

 

Try it first and decide for yourself. I had the 4.10s and am having the 5.13's put on as we speak. I could have dealt w/the 4.10s but am all about spending money on my Jeep anyway. So I would recommend you drive it first and then figure out what you want to do. My guess is that you might just end up keeping the 3.73s if a little extra zip isn't that important to you.

 

35's and 410's is just bareable, 3.73's and 35's will be worse than bareable.

How do you spell bare-able? Do you drop the e when adding the able? Might have to start a new thread for that.........or I could look it up!........

 

Flat terain city driving will be fine. It is hills at freeway speeds that its tough.

You dont have to regear it right away, drive it for a while and see what you think. Especially if you are keeping the stock tires for your trips.

 

Thanks for all of the comments! It's an auto btw for those mentioning 6 speed. I'm reassured by some of the last comments and I think I'll be fine. I laugh when I hear "hauls ***", "speed", "zip", etc partially because around here there are so many taxis and pulmonias (open air VW taxis) that you can't drive fast if you want to and then because for me....jeeps and speed have never really gone together. In college I had a stock 4 banger with 33's and yes it wasn't even remotely fast but it was a jeep so it just seemed normal.

Bolsak I'm curious about your situation, have you ever down shifted the auto so that you aren't running 1,100 RPMs? I would think that would take care of that issue and I shift my auto SUV a lot especially when in the sand to keep the RPMs where I want them.

So I'll start with the 3.73 and see how it goes. If it sucks I don't think labor would be more than $100 down here so it wouldn't kill me to regear. Just out of curiousity....what would be the right gearing then if all of my highway driving will be on the stock 32's and then around town I'm lugging the 35's at low speeds? I assume I couldn't go up much or I'd kill mpg on my road trips with the stock tires.

 

You will actually be better of with the auto. The torque converter actually will compinsate for the tires. You probably won't want to use overdrive very much.

 

Let us know how you like the new gears and some rpm specs would be nice.