Im trying to decide which gears to go with. Is there much difference in MPG between 3.42's and 3.73's? What RPM are you guys at with either one at about 60 in drive or overdrive? I do quite a bit of highway driving and don't really like to turn at too high of an RPM for an extended period of time. Thanks for the help

 

3.42's if your on the highway much

 

I'm assuming your converting from 2.73's?

If you do a lot of highway driving, stick with 3.42's. They will give you a hell of an improvement off the line, but on the highway the RPM's will be around ~2300 RPM to do ~70 mph. With 3.73's, it's up around ~2600 RPM, which is starting to get a little high. 80 mph with 3.73's is at almost 3000 RPM! With 2.73's, its just above 2000 RPM, so that's a big jump in engine speed!

Mileage wise, it's not terrible switching to 3.73's (I know from past experience) so going to 3.42's shouldn't be bad. On the highway you may lose a couple MPG, but in-town, you'll probably find you get better mileage since the motor isn't working as hard to get the car moving light-to-light. When I had 3.73's before, I actually found that my mileage was more consistantly GOOD, especially when I did a lot of city driving. Even on the highway, I still pulled over 400 kms (250 miles) on a tank of gas, and with 2.73's, I don't always get that mileage!

IMO, you'll probably be happiest with 3.42's.