I am contemplating putting a turbo the size of my head on the car. Some thing that just came up, I also have the option of putting in 4.44 gearing on both ends as I am AWD. So on my balanced, 2.0L, 8500 rpm motor, I can do either 600hp with 3.9 gearing or keeping my 450hp turbo and adding 4.44 final drive. I suspect the 4.44 would be quicker as the 600 hp turbo will only net 500 or so on pump fuel. The difference on my car would be 400 rpm or so. So on the highway at 70 mph I would spin 3500 rpm instead of 3100 rpm. The question is, assuming proper oil and oil temps is maintained etc.. is spinning the motor harder on the bearings or is cramming more power out of each power stroke harder on the bearings? Hopefully this is not a "taste great" "less filling" kind of topic.