|
|
RPM - Rear End Ratio
Chart
|
|
The chart below may
be of some help in deciding what rear end ratio is right for you.
|
|
Listed are the expected
RPM's at 60 MPH with a given rear end ratio and tire height.
|
|
This
chart applies to all Ford non-overdirve transmissions, manual and automatic.
|
|
Power
is transmitted from the transmission to rear end 1:1 in high gear.
|
Ford non-overdrive transmissions
include:
-
C-4, three-speed, automatic
-
C-6, three-speed, automatic
-
FMX, three-speed, automatic
-
Top-loader, three-speed, manual
-
Top-loader, four-speed, manual
|
|
|
For
overdrive transmission, RPM's will be approximately 32% less than shown.
|
Chart is Calculated for a Speed of
60 MPH
| |
Tire Height in Inches
|
| Ratio |
24
|
24.5
|
25
|
25.5
|
26
|
26.5
|
27
|
27.5
|
28
|
| 3.00:1 |
2520
|
2469
|
2419
|
2372
|
2326
|
2282
|
2240
|
2199
|
2160
|
| 3.25:1 |
2730
|
2674
|
2621
|
2569
|
2520
|
2472
|
2427
|
2383
|
2340
|
| 3.50:1 |
2940
|
2880
|
2822
|
2776
|
2714
|
2663
|
2613
|
2566
|
2520
|
| 3.55:1 |
2982
|
2921
|
2863
|
2807
|
2753
|
2701
|
2651
|
2602
|
2556
|
| 3.70:1 |
3108
|
3045
|
2984
|
2925
|
2869
|
2815
|
2763
|
2712
|
2664
|
| 3.80:1 |
3192
|
3125
|
3064
|
3004
|
2946
|
2891
|
2837
|
2786
|
2736
|
| 3.89:1 |
3268
|
3201
|
3137
|
3075
|
3016
|
2959
|
2905
|
2852
|
2801
|
| 4.11:1 |
3452
|
3382
|
3314
|
3249
|
3187
|
3127
|
3069
|
3013
|
2959
|
| 4.30:1 |
3612
|
3538
|
3468
|
3400
|
3334
|
3271
|
3211
|
3152
|
3096
|
| 4.62:1 |
3881
|
3802
|
3726
|
3653
|
3582
|
3515
|
3450
|
3387
|
3326
|
| 4.86:1 |
4082
|
3999
|
3919
|
3842
|
3768
|
3697
|
3629
|
3563
|
3499
|
|
|
Below
is the formula used to calculate RPMs.
|
RPM
=
|
MPH X Trans Ratio (in
high gear) X Rear End Ratio X 336
Tire Height |
|
|
|
Return
to the Previous Page
|
|
