I recently dumped about 4 quarts of used synthetic (amsoil)in my n/a rabbit. It was from a stationary natual gas generator that runs like an hour a week. the oil is changed evry year and always looks super clean. This rabbit ran good prior, but runs hellish now :evil: It will break the tire loose from a stand still. I'm gonna assume that it was the high detergent qualities of this oil that cleaned the injectors and pump. No word on milage gains yet. but i recommend it so far :lol:
I dont think I would be running SYN oils through my fuel system.
SYN oils are designed to withstand much higher temps and may not burn enough. I doubt there would be a problem with a couple Qts once in a while like you did but i wouldn't make it a habit.
Thats a good point. and I probably wouln't have a chance to get that clean of oil again or at least for a year. But, it deff. helped the old tired diesel.