Gear Ratios

[TerryMason]

Gear Ratio Calculator

Gear Ratio Calculator


This simple Gear Ratio calculator assumes that you're running around 65 MPH


All you need to do is look at your tire size on the left, then find out how many RPMs your engine is at when you are doing 65 MPH, and that will give you your Gear Ratio. the blue blocks are good gas mileage, green it a good medium and red is for more power.

[TABLE="width: 100%"]
<tbody>[TR]
[TD]



[/TD]
[TD="colspan: 14"]Gear Ratio
This chart will tell you the rpm needed to reach 65 mph



[/TD]
[/TR]
[TR]
[TD]
Tire
Size







[/TD]
[TD="bgcolor: #ffff66"]




[/TD]
[TD="bgcolor: #ffff66"]3.31[/TD]
[TD="bgcolor: #ffff66"]3.42[/TD]
[TD="bgcolor: #ffff66"]3.55[/TD]
[TD="bgcolor: #ffff66"]3.73[/TD]
[TD="bgcolor: #ffff66"]3.91[/TD]
[TD="bgcolor: #ffff66"]4.11[/TD]
[TD="bgcolor: #ffff66"]4.27[/TD]
[TD="bgcolor: #ffff66"]4.56[/TD]
[TD="bgcolor: #ffff66"]4.88[/TD]
[TD="bgcolor: #ffff66"]5.13[/TD]
[TD="bgcolor: #ffff66"]5.29[/TD]
[TD="bgcolor: #ffff66"]5.38[/TD]
[TD="bgcolor: #ffff66"]5.71[/TD]
[/TR]
[TR]
[TD="bgcolor: #ffff66"]

27



[/TD]
[TD="bgcolor: #00ffff"]2677[/TD]
[TD]2766[/TD]
[TD="bgcolor: lime"]2872[/TD]
[TD]3017[/TD]
[TD="bgcolor: red"]3163[/TD]
[TD]3325[/TD]
[TD]3454[/TD]
[TD]3689[/TD]
[TD]3947[/TD]
[TD]4150[/TD]
[TD]4279[/TD]
[TD]4352[/TD]
[TD]4619[/TD]
[/TR]
[TR]
[TD="bgcolor: #ffff66"]

28



[/TD]
[TD]2582[/TD]
[TD="bgcolor: #00ffff"]2668[/TD]
[TD]2769[/TD]
[TD="bgcolor: lime"]2909[/TD]
[TD]3050[/TD]
[TD="bgcolor: red"]3206[/TD]
[TD]3331[/TD]
[TD]3557[/TD]
[TD]3806[/TD]
[TD]4001[/TD]
[TD]4126[/TD]
[TD]4196[/TD]
[TD]4454[/TD]
[/TR]
[TR]
[TD="bgcolor: #ffff66"]

29



[/TD]
[TD]2493[/TD]
[TD]2576[/TD]
[TD="bgcolor: #00ffff"]2674[/TD]
[TD]2809[/TD]
[TD="bgcolor: lime"]2945[/TD]
[TD]3095[/TD]
[TD="bgcolor: red"]3216[/TD]
[TD]3434[/TD]
[TD]3675[/TD]
[TD]3863[/TD]
[TD]3984[/TD]
[TD]4052[/TD]
[TD]4300[/TD]
[/TR]
[TR]
[TD="bgcolor: #ffff66"]

30



[/TD]
[TD]2410[/TD]
[TD]2490[/TD]
[TD="bgcolor: #00ffff"]2584[/TD]
[TD]2715[/TD]
[TD="bgcolor: lime"]2846[/TD]
[TD]2992[/TD]
[TD="bgcolor: red"]3109[/TD]
[TD]3320[/TD]
[TD]3553[/TD]
[TD]3735[/TD]
[TD]3851[/TD]
[TD]3917[/TD]
[TD]4157[/TD]
[/TR]
[TR]
[TD="bgcolor: #ffff66"]

31



[/TD]
[TD]2332[/TD]
[TD]2409[/TD]
[TD]2501[/TD]
[TD="bgcolor: #00ffff"]2628[/TD]
[TD]2755[/TD]
[TD="bgcolor: lime"]2896[/TD]
[TD]3008[/TD]
[TD="bgcolor: red"]3213[/TD]
[TD]3838[/TD]
[TD]3614[/TD]
[TD]3727[/TD]
[TD]3790[/TD]
[TD]4023[/TD]
[/TR]
[TR]
[TD="bgcolor: #ffff66"]

32



[/TD]
[TD]2259[/TD]
[TD]2334[/TD]
[TD]2423[/TD]
[TD="bgcolor: #00ffff"]2546[/TD]
[TD]2696[/TD]
[TD="bgcolor: lime"]2805[/TD]
[TD]2914[/TD]
[TD="bgcolor: red"]3112[/TD]
[TD]3331[/TD]
[TD]3501[/TD]
[TD]3610[/TD]
[TD]3672[/TD]
[TD]3897[/TD]
[/TR]
[TR]
[TD="bgcolor: #ffff66"]

33



[/TD]
[TD]2191[/TD]
[TD]2263[/TD]
[TD]2349[/TD]
[TD]2469[/TD]
[TD="bgcolor: #00ffff"]2588[/TD]
[TD]2720[/TD]
[TD="bgcolor: lime"]2826[/TD]
[TD]3018[/TD]
[TD="bgcolor: red"]3230[/TD]
[TD]3395[/TD]
[TD]3501[/TD]
[TD]3561[/TD]
[TD]3779[/TD]
[/TR]
[TR]
[TD="bgcolor: #ffff66"]

34



[/TD]
[TD]2126[/TD]
[TD]2197[/TD]
[TD]2280[/TD]
[TD]2396[/TD]
[TD]2512[/TD]
[TD="bgcolor: #00ffff"]2640[/TD]
[TD]2743[/TD]
[TD="bgcolor: lime"]2929[/TD]
[TD]3135[/TD]
[TD="bgcolor: red"]3295[/TD]
[TD]3398[/TD]
[TD]3456[/TD]
[TD]3668[/TD]
[/TR]
[TR]
[TD="bgcolor: #ffff66"]

35



[/TD]
[TD]2065[/TD]
[TD]2134[/TD]
[TD]2215[/TD]
[TD]2328[/TD]
[TD]2440[/TD]
[TD="bgcolor: #00ffff"]2565[/TD]
[TD]2664[/TD]
[TD="bgcolor: lime"]2845[/TD]
[TD]3045[/TD]
[TD="bgcolor: red"]3201[/TD]
[TD]3301[/TD]
[TD]3357[/TD]
[TD]3563[/TD]
[/TR]
[TR]
[TD="bgcolor: #ffff66"]

36



[/TD]
[TD]2008[/TD]
[TD]2075[/TD]
[TD]2154[/TD]
[TD]2263[/TD]
[TD]2372[/TD]
[TD]2493[/TD]
[TD="bgcolor: #00ffff"]2590[/TD]
[TD]2766[/TD]
[TD="bgcolor: lime"]2961[/TD]
[TD]3112[/TD]
[TD="bgcolor: red"]3209[/TD]
[TD]3264[/TD]
[TD]3464[/TD]
[/TR]
[TR]
[TD="bgcolor: #ffff66"]

37



[/TD]
[TD]1954[/TD]
[TD]2019[/TD]
[TD]2095[/TD]
[TD]2203[/TD]
[TD]2308[/TD]
[TD]2426[/TD]
[TD="bgcolor: #00ffff"]2520[/TD]
[TD]2692[/TD]
[TD="bgcolor: lime"]2881[/TD]
[TD]3028[/TD]
[TD="bgcolor: red"]3123[/TD]
[TD]3176[/TD]
[TD]3370[/TD]
[/TR]
[TR]
[TD="bgcolor: #ffff66"]

38



[/TD]
[TD]1902[/TD]
[TD]1966[/TD]
[TD]2040[/TD]
[TD]2144[/TD]
[TD]2247[/TD]
[TD]2362[/TD]
[TD]2454[/TD]
[TD="bgcolor: #00ffff"]2621[/TD]
[TD]2805[/TD]
[TD="bgcolor: lime"]2948[/TD]
[TD]3040[/TD]
[TD="bgcolor: red"]3092[/TD]
[TD]3282[/TD]
[/TR]
[TR]
[TD="bgcolor: #ffff66"]

39



[/TD]
[TD]1854[/TD]
[TD]1915[/TD]
[TD]1988[/TD]
[TD]2089[/TD]
[TD]2190[/TD]
[TD]2302[/TD]
[TD]2391[/TD]
[TD="bgcolor: #00ffff"]2554[/TD]
[TD]2733[/TD]
[TD="bgcolor: lime"]2873[/TD]
[TD]2962[/TD]
[TD="bgcolor: red"]3013[/TD]
[TD]3198[/TD]
[/TR]
[TR]
[TD="bgcolor: #ffff66"]

40



[/TD]
[TD]1807[/TD]
[TD]1867[/TD]
[TD]1938[/TD]
[TD]2037[/TD]
[TD]2135[/TD]
[TD]2244[/TD]
[TD]2331[/TD]
[TD]2490[/TD]
[TD="bgcolor: #00ffff"]2664[/TD]
[TD]2801[/TD]
[TD="bgcolor: lime"]2888[/TD]
[TD]2937[/TD]
[TD="bgcolor: red"]3118[/TD]
[/TR]
[TR]
[TD="bgcolor: #ffff66"]

41



[/TD]
[TD]1763[/TD]
[TD]1822[/TD]
[TD]1891[/TD]
[TD]1987[/TD]
[TD]2083[/TD]
[TD]2189[/TD]
[TD]2275[/TD]
[TD]2429[/TD]
[TD="bgcolor: #00ffff"]2599[/TD]
[TD]2733[/TD]
[TD="bgcolor: lime"]2818[/TD]
[TD]2866[/TD]
[TD="bgcolor: red"]3042[/TD]
[/TR]
[TR]
[TD="bgcolor: #ffff66"]

42



[/TD]
[TD]1721[/TD]
[TD]1778[/TD]
[TD]1846[/TD]
[TD]1940[/TD]
[TD]2033[/TD]
[TD]2137[/TD]
[TD]2220[/TD]
[TD]2371[/TD]
[TD]2538[/TD]
[TD="bgcolor: #00ffff"]2668[/TD]
[TD]2751[/TD]
[TD="bgcolor: lime"]2798[/TD]
[TD]2969[/TD]
[/TR]
[TR]
[TD="bgcolor: #ffff66"]

43



[/TD]
[TD]1681[/TD]
[TD]1737[/TD]
[TD]1803[/TD]
[TD]1894[/TD]
[TD]1986[/TD]
[TD]2087[/TD]
[TD]2169[/TD]
[TD]2316[/TD]
[TD]2479[/TD]
[TD="bgcolor: #00ffff"]2606[/TD]
[TD]2687[/TD]
[TD="bgcolor: lime"]2733[/TD]
[TD]2900[/TD]
[/TR]
[TR]
[TD="bgcolor: #ffff66"]

44



[/TD]
[TD]1643[/TD]
[TD]1698[/TD]
[TD]1762[/TD]
[TD]1851[/TD]
[TD]1941[/TD]
[TD]2040[/TD]
[TD]2119[/TD]
[TD]2263[/TD]
[TD]2422[/TD]
[TD]2546[/TD]
[TD="bgcolor: #00ffff"]2626[/TD]
[TD]2670[/TD]
[TD="bgcolor: lime"]2834[/TD]
[/TR]
</tbody>[/TABLE]

<tbody>
[TD="bgcolor: #00ffff"]

Blue = 2600 RPM​

Better Mileage​

[/TD]
[TD="width: 33%, bgcolor: #00ff00"]

Green = 2800 RPM
Around factory​

[/TD]
[TD="width: 34%, bgcolor: #ff0000"]Red = 3100
RPM
Good Power


[/TD]

</tbody>

 

[kawstxf15]

Re: Jeep Gear Ratio Calculator

Terry,

Should I assume I am driving in 5th gear to reach 65mph, please confirm the gear.

 

[captjanes]

i have a four cyl jeep and i put a 4 inch lift and 35 inch tires my jeep cant go fast enough to put her in 5th gear i drive aeround in 3rd and 4th gear and she can only do 100 km/h.. i want my jeep to go faster and have more power for in the mud and in sand.. can u plz tell me what to do with my jeep

 

[Bounty__Hunter]

i have a four cyl jeep and i put a 4 inch lift and 35 inch tires my jeep cant go fast enough to put her in 5th gear i drive aeround in 3rd and 4th gear and she can only do 100 km/h.. i want my jeep to go faster and have more power for in the mud and in sand.. can u plz tell me what to do with my jeep

Regear the axles to 4.88, that is as low as you can go with the stock axles, even though lower is better.

 

[Bounty__Hunter]

Re: Jeep Gear Ratio Calculator

Terry,

Should I assume I am driving in 5th gear to reach 65mph, please confirm the gear.

I think it would be 4th, or 1:1 transmission ratio.

Regardless of transmission gear, find your stock gear ratio on top and move down until your at your stock tire size. Record that RPM. Then move to your current or desired tire size and move across the chart to the right until you find an RPM similar to the previous number. Move up and find the suggested gear ratio for the new tire size.

 

[captjanes]

so what ur saying is that to get more speed and power out of my jeep i has to change the gears in the front and rear differentials axels? someone told me that i had to change a gear in the transmission is this true or do i just have to regear the axels? and can u tell me how about going to regear the axles.. where can i order gears to? thanks in advanced

 

[Team Twisted Off Road]

Hello to terry mason.. I have been looking into 4:88 gears and have found that your chart is wrong 31" tires and 4:88 gears you have 3838 and it should be 3438 thanks team twisted off road.

 

[Bounty__Hunter]

Hello to terry mason.. I have been looking into 4:88 gears and have found that your chart is wrong 31" tires and 4:88 gears you have 3838 and it should be 3438 thanks team twisted off road.

It's all relative to what gear the transmission is in, and isn't really necessary information to use the chart.

To simply use the chart, find the given RPM for stock tire size and stock gear ratio. Then go the line of the tire you want to run, and move over until you find a similar RPM, or slightly higher, that is your recommended gear ratio.

 

[Team Twisted Off Road]

it's all relative to what gear the transmission is in, and isn't really necessary information to use the chart.

To simply use the chart, find the given rpm for stock tire size and stock gear ratio. Then go the line of the tire you want to run, and move over until you find a similar rpm, or slightly higher, that is your recommended gear ratio.

 

[BaconYJ]

I have found this program to be very helpful when trying to figure out crawl speeds, ratios, rpms etc.

Gear Ratio Calculator

Bacon

 

[rudedog14]

Re: Jeep Gear Ratio Calculator

I am new. In what gear? I have 5 speed manual, 4 cylinder with 35" tires. I think the previous owner put the big tires on to look cool without thinking about the effects it would have on performance. Any of your suggestions will be highly regarded. Thanks in advance for the help.

 

[Bounty__Hunter]

Welcome to the Z. 4.88 is as low as you can go with the stock axles, so that's your best choice.

I run a 2.5L 5spd and 35" tires, 5.38 gears work perfect for me but I had to upgrade to Dana 44 axles.

 

[rudedog14]

Thanks Bounty_Hunter

 

[carnuck]

I use the calculators on 4LO.COM :: On-Line Gear/Tire Size Calculators