I've used it in 5W30 in my snow blower, ( which actually calls for 5W30),, and old Toyota's that call for 5W30. No problems with it. Stayed clean in the snow blower,,going on 3 seasons now with the same oil. So it's not cooking up in that little 5hp Tecumseh. As for the Toyota's, they get 3 month or 3k oil changes anyway ( whichever comes first ). Checked the dipsticks, their not turning black either. So the oil isn't cooking in the Toyota's. Good enough for me. Don't know you're oil change intervals, so I can't advise any furthur than 3 months or 3K.