case 446 owner
I have a 446 with an onan. I use 15w40 in the hydraulic system, would it hurt anything to use it in the engine also?
This is true. I use Amsoil 10w30 or 5w30 during the winter in my b43m Onan 446 and things start much easier. Less strain on the battery too.:fing32:Synthetic oil is very important at those temps. Not only will it start easier but will provide much better protection