I think after run oil is a good idea to use after you done running the car or truck for the day. The oil WILL NOT damage any seals in the engine, you could soak the engine in after run oil if you wanted and not have a problem, it is pure oil. The only problem I foresee with using after run oil is it is a little difficult to start the engine the next time you want to run your car or truck.

TIP - You could use automatic transmission fluid as after run oil if you wanted too. Transmission fluid is pretty much the same type of oil as after run oil.