I live in New Hampshire. It gets cold here, not like Northern Canada or Alaska ( I spent 2 years in Alaska's interior and have seen -65º) but down to -20º from time to time. That said, I would not try to start my RTV900 much below +10º. This is a 2010 machine I just purchased and it has marked on the exhaust shield 3½ qts 15w-40. I can't find that oil listed, only 10w30 or 10w40. What do other people use? Rotella T 15w-40? Something from Kubota?