Instructions: Input axle ratio, transmission ratio, tire diameter, and vehicle speed for up to three different drivetrain combinations to view engine speed (RPM) under those conditions.
*For automatic transmissions, calculations will only be accurate under the assumption that the torque converter is locked.
**Advertised tire sizes are nominal values. For best results, measure actual tire height to nearest 1/4 inch.
Common Transmission Ratio Chart
Transmission |
1st |
2nd |
3rd |
4th |
5th |
6th |
R |
GM TH350 |
2.52 |
1.52 |
1.00 |
- |
- |
- |
2.07 |
GM TH400 |
2.48 |
1.48 |
1.00 |
- |
- |
- |
2.07 |
Ford C4 |
2.46 |
1.46 |
1.00 |
- |
- |
- |
2.18 |
Ford C6 |
2.46 |
1.46 |
1.00 |
- |
- |
- |
2.18 |
Chrysler 727 |
2.45 |
1.45 |
1.00 |
- |
- |
- |
2.20 |
Chrysler 47RE/47RH |
2.45 |
1.45 |
1.00 |
0.69 |
- |
- |
2.21 |
Chrysler 48RE |
2.45 |
1.45 |
1.00 |
0.69 |
- |
- |
2.21 |
Ford AOD/AODE |
2.40 |
1.47 |
1.00 |
0.67 |
- |
- |
2.00 |
Ford E4OD |
2.71 |
1.54 |
1.00 |
0.71 |
- |
- |
2.18 |
GM 4L60E |
3.06 |
1.63 |
1.00 |
0.70 |
- |
- |
2.29 |
GM 4L80E |
2.48 |
1.48 |
1.00 |
0.75 |
- |
- |
2.07 |
Ford 4R100 |
2.71 |
1.54 |
1.00 |
0.71 |
- |
- |
2.18 |
Chrysler 68RFE |
3.23 |
1.84 |
1.41 |
1.00 |
0.82 |
0.63 |
4.44 |
Ford 5R110W (TorqShift 5) |
3.11 |
2.20 |
1.54 |
1.00 |
0.71 |
- |
2.88 |
Ford 6R140 (TorqShift 6) |
3.97 |
2.32 |
1.52 |
1.15 |
0.86 |
0.67 |
3.28 |
Allison 1000 (5 spd) |
3.09 |
1.81 |
1.41 |
1.00 |
0.71 |
- |
4.48 |
Allison 1000 (6 spd) |
3.09 |
1.81 |
1.41 |
1.00 |
0.71 |
0.61 |
4.48 |
Aisin AS69RC |
3.75 |
2.00 |
1.34 |
1.00 |
0.77 |
0.63 |
3.54 |
Muncie SM465 |
6.55 |
3.58 |
1.57 |
1.00 |
- |
- |
6.09 |
Borg Warner T-19 |
4.02 |
2.41 |
1.41 |
1.00 |
- |
- |
6.96 |
GETRAG G360 |
5.53 |
3.02 |
1.60 |
1.00 |
0.77 |
- |
5.03 |
New Venture NV4500 (Dodge) |
5.61 |
3.04 |
1.67 |
1.00 |
0.75 |
- |
5.61 |
New Venture NV4500 (late GM) |
5.61 |
3.04 |
1.67 |
1.00 |
0.75 |
- |
5.61 |
New Venture NV4500 (early GM) |
6.34 |
3.44 |
1.71 |
1.00 |
0.73 |
- |
6.34 |
New Venture NV5600 |
5.63 |
3.38 |
2.04 |
1.39 |
1.00 |
0.73 |
5.63 |
ZF S5-42, S5-47 (wide ratio) |
5.72 |
2.94 |
1.61 |
1.00 |
0.76 |
- |
5.24 |
ZF S6-650, S6-750 |
5.79 |
3.30 |
2.10 |
1.31 |
1.00 |
0.72 |
5.23 |
Mercedes G56 (05 - 07) |
6.29 |
3.48 |
2.10 |
1.38 |
1.00 |
0.79 |
6.29 |
Mercedes G56 (07.5+) |
5.94 |
3.28 |
1.98 |
1.31 |
1.00 |
0.74 |
5.42 |
For more information on transmissions found in diesel applications, see transmission tech @ Diesel Hub.