I think I have asked this before. But I have a 52 in Exmark with a Kohler 23 hp engine and a 36 in Exmark wb with a kawasaki 12.5 hp and I need to know what weight oils you guys are running? I was looking at Mobil 1 full synthetic sae 10w - 30. Is this ok or overkill at 4.99/quart? Or should I just use a straight SAE 30 oil? Or should I use 5w-20 oil? Some help, I don't want to put the wrong thing in my mowers. Thanks.