My own personal difference (a bit jokingly but with some truth) is L stands for lawn care, while M stands for Much preferred The M series is for agricultural applications, with a larger frame and other heavy duty benefits. Therefore, the same HP tractor in the L series is, IMHO, much less tractor than in the M series with,sometimes, not that much price difference (at least in the case of Grand (paw) L series). Wish someone had pointed this out to me in the beginning, but I now have the M and would never look at the L again good luck bb.