Hi there, Just bought a mint 2012 model and have come across this topic all over the interweb. Some are adamant that ALL GS500's use oil, while others dispute that claim. I'm so CONFOOOOSED! Just looking for some personal experiences from my fellow Netriders/GS500 owners, please... Also, I know Suzuki recommend 10-40W oil. (It's printed on the oil filler cap, for God's sake!) However, in Melbourne, for punting around the hills / sport touring, is 15-50W mineral oil acceptable?