A bit from Wikipedia on twin plug heads. The Ford Ranger picked up about 10% extra horsepower with the change. The Ducati gained 5% in Max torque. Those are big gains.
Dual ignition promotes engine efficiency by initiating twin flame fronts, giving faster and more complete burning and thereby increasing power.[6] Although a dual ignition system is a very effective method of achieving optimum combustion and better fuel consumption, it remains rare in cars and motorcycles because of difficulties in siting the second plug. Alfa Romeo Twin Spark cars (eponymously) use dual ignition, as do Honda cars with the i-DSI series engines[7] and Chrysler'sModern Hemi engine. In 1980 Nissan installed twin sparkplugs on the Nissan NAPS-Z engine, with Ford introducing it on the 1989 Ford Ranger and 1991 Ford Mustang four-cylinder models. Several modern Mercedes-Benz engines also feature two spark plugs per cylinder, e.g. the M112 and M113 engines. Some motorcycles, such as the Honda VT500, the Honda NT400 Bros, and the BMW R1100S also employ dual ignition.[8] The 2012 Ducati Multistrada was upgraded with "twin-plug cylinder heads for smoother, more efficient combustion", the change contributing to a 5% increase in torque and a 10% improvement in fuel consumption.[9]
), it becomes a bit academic. Any time you can reduce ignition advance it is a good thing as the engine does less wasted work compressing an igniting charge and as worntorn has pointed out, this also allows one to do other things to enhance the motors performance.
