need advice for gear ratio
#1
#7
4.56 will get you in your "close to stock" rpm at a given highway speed. 4.88 will get you more POWER less gas milage. the rule of thumb for tire to gear ratio calculation is to multiply .12 by your tire diameter. (.12 X 38" = 4.56)
my 96 ZJ has 37" tires and i run 4.56s and i have pretty good get up and go go
check out 4Lo.com :: Gear Ratio & Tire Size Chart
my 96 ZJ has 37" tires and i run 4.56s and i have pretty good get up and go go
check out 4Lo.com :: Gear Ratio & Tire Size Chart
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#8
Join Date: Jun 2006
Location: Ottawa, Ontario
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What transmission do you have?
There is no one stock gear ratio you could have one of several options, but that said the ideal power vs fuel milage ratio with stock 31" tires is 3.55 to 3.73, and to get that with 36" tires you need 4.10 to 4.30.
Also of high importance particularly if you have the E4OD trans is that the PSOM(speedo) be recalibrated for the larger tires. The computer controls this transmission with input from all sensors including the speedo and an accurate input is vital to proper trans operation. An accurate speedo will also improve fuel milage simply because if it's not recalibrated you're actually travelling faster than indicated which burns more fuel, and because the odometer isn't racking up as many miles as it should.
There is no one stock gear ratio you could have one of several options, but that said the ideal power vs fuel milage ratio with stock 31" tires is 3.55 to 3.73, and to get that with 36" tires you need 4.10 to 4.30.
Also of high importance particularly if you have the E4OD trans is that the PSOM(speedo) be recalibrated for the larger tires. The computer controls this transmission with input from all sensors including the speedo and an accurate input is vital to proper trans operation. An accurate speedo will also improve fuel milage simply because if it's not recalibrated you're actually travelling faster than indicated which burns more fuel, and because the odometer isn't racking up as many miles as it should.
#10
Ditch those 37" tires. Good gas mileage and big tires do not belong in the same sentence. Go to something more reasonable like 31" to 33" tires. All the money you would spend on gears could be saved by going to a shorter/narrower tire.
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