When I use the tractor (JD2305) to clean up around the yard, I usually turn it off if I am going to be off it for more than 10 minutes or so, using the chain saw or something like that. When I jump off to pick up something and throw it on the carryall, I leave it running (parking brake set). I have noticed that in truck stops the drivers leave their diesel engines running for long periods of time. I know that a lot of wear happens during starting as the oil pump is building pressure. So is 10 minutes a reasonable amount of time or should I lengthen it and if so, how long?