Mercury - Quicksilver 20W-50 Synthetic Motorcycle Oil V-Twin 4-Stroke Engine Protection High-Heat Synthetic Blend 8M0166407. Overview. If you ride a V-twin, you get it - these engines run hot, hard and with a rhythm all their own. They rumble through long summer rides, idle patiently in traffic and carry you mile after mile with that unmistakable heartbeat. To keep a motor like that healthy, you don't just pour in any oil. You choose something built for the heat, the pressure and the personality