Listed gear-ratio data for 2013 Mariner 40 HP outboards. Match your exact model and lower unit; some models may have more than one gearcase configuration.
2013 Mariner 40 HP
Listed ratio values: 2.00:1, 2.33:1
| Model | Gear ratio |
|---|---|
| F40 EFI BigFoot | 2.33:1 |
| F40 EFI FourStroke | 2.00:1 |
Use the ratio that matches your exact outboard model and lower unit, then enter it in the PropSlip calculator.