What gear ratio for 33s on an AW4?

[GeologistFelix]

Ok, so, right now, I get around 1900rpm with an AW4, 30" tires, and 3.55 gears when going 60mph (average highway speed around here). What I recall is that the 4.0L gets the best mileage at around 2200 to 2600 rpm...

So, when I did the math for 33" tires and a regear, I found that I'd be getting 2000 rpms with 4.11 gears (the commonly recommended ratio for an auto transmission and 33s, but in wranglers with the 3-speed auto), 2200 with 4.56 (which seem to be the most popular ratio for 33s), and about 2400 with 4.88.

Obviously, the 4.88 gears are going to best offroad, but I'm wondering more about minimizing gas-guzzling with the 33s. So, I guess the real question at the heart of all of this is...how many RPMs should you be running at to maximize mileage at 60mph?

[xjfever]

4:56 Is the best gearing for 33" tires and the AW4.

[Eman]

Originally Posted by xjfever

4:56 Is the best gearing for 33" tires and the AW4.

would be best, but i drive 50miles highway each day, and am a cheap bastard. so i pulled a set of 4.10s out of a 4cyl for my 33s

[xjfever]

With 4:10 gears you will be 2190 at 70 mph, with 4:56 you will be 2430 at 70 mph. The 4:56 will help you to maintain overdrive on the highway when hitting an incline where with 4:10 gears you will drop to third gear a lot more often. This will result in better mileage from the 4:56 gears. And around town there is no question that you will get better mileage from the 4:56 gears.

[justanotherjpr]

Originally Posted by xjfever

With 4:10 gears you will be 2190 at 70 mph, with 4:56 you will be 2430 at 70 mph. The 4:56 will help you to maintain overdrive on the highway when hitting an incline where with 4:10 gears you will drop to third gear a lot more often. This will result in better mileage from the 4:56 gears. And around town there is no question that you will get better mileage from the 4:56 gears.

X2 on this. Go with 4.56's and never look back.