Mobile 1 was always reccomended because it is one of only a very few truely synthetic oils. Almost all so called synthetic oils are really just modified high grade mineral oils (API 3). Any V-twin 20w 50 oil that has API 4 in its spec is the same - as Mobile 1. These true syntetic oils perform more reliably under tough conditions, most bike the X-wedge were designed for never weighed as much as the M3W!
