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Home > Gear Ratio Guide for Larger Tires
Ring & Pinion Gear Ratio Guide for Larger Tires
 

When ever you change tire size from the original size to another there will be a direct effect on power and drivability. We have developed this chart to help you select the optimum gear ratio to put your performance back where you want it.

Using the chart below, first determine your original gear ratio and tire size and follow to the intersection that should be your approximate RPM at 65 MPH. Next find your new tire size and follow that across to the closest RPM to your original and that will be first choice. 

If you are interested in a change that will give more power or better fuel mileage use the color coding as a guide.
 
         Highway Driving, Good Fuel Economy
  Daily Driver, Best Overall Performance
  Most Power and Towing, Reduced Fuel Economy

This chart is based on 65 MPH and a gear ratio of 1:1, on a manual transmission in 4th gear.

Please NOTE: If you have an automatic transmission your RPM will higher due to slippage in the transmission and the torque converter. With an overdrive transmission your RPM in overdrive will be 15% to 30% less than indicated.
 
 
 
 
 
Gear Ratio
Tire Diameter
 
2.35
2.73
2.94
3.07
3.21
3.31
3.42
3.55
3.73
3.91
4.11
4.27
4.56
4.88
5.13
5.29
5.38
5.71
6.17
7.17
22
2333
2710
2919
3048
3178
3286
3395
3524
3703
3882
4080
4239
4527
4845
5093
5252
5341
5668
6125
7118
23
2231
2592
2792
2915
3048
3143
3248
3371
3542
3713
3903
4055
4330
4634
4871
5023
5109
5422
5859
6808
24
2139
2484
2675
2794
2921
3012
3112
3231
3394
3558
3740
3886
4150
4441
4668
4814
4896
5196
5615
6525
25
2053
2385
2568
2682
2804
2892
2988
3101
3259
3416
3590
3730
3984
4263
4482
4621
4700
4988
5390
6264
26
1974
2293
2470
2579
2696
2780
2873
2982
3133
3284
3452
3587
3830
4099
4309
4444
4519
4796
5183
6023
27
1901
2208
2378
2483
2597
2677
2766
2872
3017
3163
3325
3454
3689
3947
4150
4279
4352
4619
4991
5800
28
1833
2129
2293
2395
2504
2582
2668
2769
2909
3050
3206
3331
3557
3806
4001
4126
4196
4454
4813
5593
29
1770
2056
2214
2312
2417
2493
2576
2674
2809
2945
3095
3216
3434
3675
3863
3984
4052
4300
4647
5400
30
1711
1987
2140
2235
2337
2410
2490
2584
2715
2846
2992
3109
3320
3553
3735
3851
3917
4157
4492
5220
31
1656
1923
2071
2163
2261
2332
2409
2501
2628
2755
2896
3008
3213
3438
3614
3727
3790
4023
4347
5051
32
1604
1863
2007
2095
2191
2259
2334
2423
2546
2669
2805
2914
3112
3331
3501
3610
3672
3897
4211
4894
33
1555
1807
1946
2032
2124
2191
2263
2349
2469
2588
2720
2826
3018
3230
3395
3501
3561
3779
4083
4745
34
1510
1754
1889
1972
2062
2126
2197
2280
2396
2512
2640
2743
2929
3135
3295
3398
3456
3668
3963
4606
35
1466
1704
1835
1916
2003
2065
2134
2215
2328
2440
2565
2664
2845
3045
3201
3301
3357
3563
3850
4474
36
1426
1656
1784
1862
1947
2008
2075
2154
2263
2372
2493
2590
2766
2961
3112
3209
3264
3464
3743
4350
37
1387
1611
1735
1812
1895
1954
2019
2095
2202
2308
2426
2520
2692
2881
3028
3123
3176
3370
3642
4232
38
1351
1569
1690
1764
1845
1902
1966
2040
2144
2247
2362
2454
2621
2805
2948
3040
3092
3282
3546
4121
39
1316
1529
1646
1719
1798
1854
1915
1988
2089
2190
2302
2391
2554
2733
2873
2962
3013
3198
3455
4015
40
1283
1491
1605
1676
1753
1807
1867
1938
2037
2135
2244
2331
2490
2664
2801
2888
2937
3118
3369
3915
41
1252
1454
1566
1635
1710
1763
1822
1891
1987
2083
2189
2275
2492
2599
2733
2818
2866
3042
3287
3819
42
1222
1420
1529
1596
1669
1721
1778
1846
1940
2033
2137
2220
2371
2538
2668
2751
2798
2969
3208
3728
43
1194
1387
1493
1559
1630
1681
1737
1803
1894
1986
2087
2169
2316
2479
2606
2687
2733
2900
3134
3642
44
1166
1355
1459
1524
1593
1643
1698
1762
1851
1941
2040
2119
2263
2422
2545
2626
2670
2834
3063
3559