The photos show an Optima with an onroad configuration and then an offroad one. The only difference is the tires being installed.
As you can see, the onroad tires are smaller than the offroad spike tires. Smaller tires are always easier for the entire drive system.
The car runs fine onroad. However, the motor fails quickly when running over grassland.
Seems like it has to deal with the fact that gearing has been too aggressive. When running onroad the smaller tires do not introduce problems. But on grassland the larger spike tires become too “heavy” for the motor.
I should have switched to a smaller pinion to avoid the problem.


