Originally Posted by MSD

At low rpm the MSD produces a series of sparks during each firing instead of one like a conventional ignition. At low engine speeds when the air/fuel molecules are not finely atomized, the multiple spark feature still ignites the mixture. But this isn't the only feature. The number of sparks produced by the MSD Is reduced as engine rpm increases simply because "time" becomes too short to repeat a spark. However, the spark series always lasts for 20 degrees of crankshaft rotation no matter what the rpm and no matter whether it is a single spark or a series of four or five sparks. This 20 degree duration spark sequence insures that the air/fuel mixture is ignited and completely burned. Also each spark the MSD produces is an extremely high current spark. Current is like the heat of the flamethrower. Current is what actually does the work or in this case ignites the fuel mixture. Together, the multiple sparks, the high current and the 20 degree duration, produce an ignition that is superior to any other ignition. More importantly though, the MSD Ignition ignites the fuel mixture in the cylinder instantly and insure complete combustion, no matter what the molecular composition is. The result is reduced variations in burn times and therefore more engine power, better throttle response, easier starting and better fuel economy.