The key to DSF is using signal processing software to monitor the entire engine. It's primarily a software solution, but some extra complexity is added because each cylinder needs to be equipped with deactivation hardware. However, according to Tula CEO Scott Bailey, this is fundamentally the same equipment that exists today; the processing power just wasn't available before to make these types of dynamic decisions happen.
Of course, altering the fire order constantly could introduce some pretty gnarly vibrations to the engine. According to Bailey, the software is constantly asking, "Do we need to fire for torque or not?" If the answer is yes, then the affect on vibration is also considered, and the software allows the appropriate cylinder to spark. It can work on practically any multi-cylinder engine whether inline or in some other configuration.
Bailey couldn't specifically say when we might see DSF on sale in production vehicles, but "the technology is viewed as production worthy." General Motors Ventures is among Tula's investors, and the company says the technology could appear in some of its future models. The business is also working with other global automakers to possibly bring the solution to market.