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Why not 4.10 gears with 37’s on the 392?

alksion

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I had same issue using waze then realized that when plugged into Apple Play the speed reported in the app is off the speedo and not GPS. I unplugged from Apple Play and the Waze reported speed thru the app and on the iPhone rather than on the Uconnect screen mirrored my GPS enabled radar detector and about 10 MPH different than speedo at 75 MPH reported on Speedo, net net GPS = 85 MPH. This is not a linear relationship and the delta smaller at slower speeds.

Fun fact, the KO2 37" tires will pull the speedo below actual speed and thus allow shooting beyond the speed limiter since the limiter is tied to speedo which is now inaccurate unless recalibrated via Taser Mini/AEV module, etc - so I am told and speaking hypothetically :).
I was going about 4 MPH more than what Waze was saying. Not too bad.
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Philip

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Using some back of the napkin math tells me that 4.18 gears with 37 inch tires would be equivalent to the 392 stock configuration of 3.73 gears with 33 inch tires.

Since 4.18 gears are not a thing...4.10 would be the closest.

So...why do most people tend to lean towards 4.56 or 4.88?

I am assuming for greater acceleration and rock crawling at the expense of higher RPMs at highway speeds and reduced fuel economy?

I ask because I am planning to re-gear at some point soon and want to make an informed decision.

I appreciate any input.
The short answer to your question is: Weight, not tire size, is the reason you would regear your 392. You’ll get your acceleration and 8th gear back!

My wife and I have two 392s. One is for off-road and the other is for getting groceries.

The grocery getter is lightly-modified (35” Cooper STT’s w/ KMC Beadlocks, a poison spider bumper, Warn xenon 10s, and RC tire carrier, and Rockhard sliders) and does absolutely fine on the 3.73 gears.

Our off-roader, however, is ~4” taller, 1,000+ lbs heavier (mods, armor and tools), and rarely ever saw 8th gear… until I moved to 4.56 gears… and now I’m back to drag racing again!
Jeep Wrangler JL Why not 4.10 gears with 37’s on the 392? 18D9FCE8-1A44-43F7-9AF7-0377F883AD50
 
 



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