palmettobackwoods
NAXJA Forum User
- Location
- Charleston,SC
would it not be better to run a higher gear ratio with bigger tires?
While I don't think I've ever questioned anything you've ever posted, that sounds high. I thought that, with stock 215/75/15 or 225/70/15 tires (only a .3" difference between them), the RPMs would be around 2100 at 65 m.p.h. with the 4.0L and AW4 combo. I understand that we don't want the tranny lugging along at too-low RPMs.5-90 said:Typically, you want to set up so that you end up cruising around 3000rpm at whatever speed you use most (default: freeway speed.)
Yea that is a good starting point. Usually deeper is better for off roading. Especially when you want control over wheel speed. If you want wheel speed, ie mudin, then you dont want to go deep like you would for say rock crawling.99XJWhitey said:What is your exact setup and what will you be using it for? Lets start there.
Timber said:While I don't think I've ever questioned anything you've ever posted, that sounds high. I thought that, with stock 215/75/15 or 225/70/15 tires (only a .3" difference between them), the RPMs would be around 2100 at 65 m.p.h. with the 4.0L and AW4 combo. I understand that we don't want the tranny lugging along at too-low RPMs.
Very good, then. May I then surmise that the reason Jeep was keeping the RPMs lower was almost strictly for better fuel efficiency?5-90 said:"Around" is a little vague - I think I usually cruise at 2700-2800 (88/3.07/4th/30's.) I still want to re-gear one of these days, but I've had larger things to do.
If you search up, there are a couple of threads on engine efficiency vice crankshaft speed, and it's not just me saying this. I've taken the time to verify it (as much as possible) experimentally, but experiences seem to have shown that this is a good target for cruising speeds.
Timber said:Very good, then. May I then surmise that the reason Jeep was keeping the RPMs lower was almost strictly for better fuel efficiency?
EDIT: Sorry, not trying to hijack this thread.
XBoBJ said:how do you know all this stuff 5-90 your a jeep connoisseur
tayman said:I'll be your consultant for say..... 30%?:eyes: