Listed gear-ratio data for 1999 Mercury 135 HP DFI / OptiMax outboards. Match your exact model and lower unit; some models may have more than one gearcase configuration.
1999 Mercury 135 HP DFI / OptiMax
Listed ratio values: 2.00:1
| Model | Gear ratio |
|---|---|
| 1996-2018 | 2.00:1 |
Use the ratio that matches your exact outboard model and lower unit, then enter it in the PropSlip calculator.