Mechanically-speaking, the internal combustion has changed little in the last century, refinements enabling more power and better fuel economy, but there are limits.
The first electronic controls on internal combustion engines appeared some forty years ago, tuning for more refined spark delivery, better power output, better fuel economy, and fewer emissions. Fast-forward forty years, and the modern automobile has dozens of computer controls and sensors for the engine alone, and dozens more for the rest of the vehicle. Regarding fuel economy, however, mechanical advances and computer technology seemed to have reached their limits.
New software and computer controls could make for even better fuel economy, says Tula Technology and major backer General Motors. The new hardware/software combination is called Dynamic Skip Fire, and is basically Cylinder Deactivation on steroids, a fuel-saving technology already in use in many modern vehicles. Cylinder deactivation schemes are limited in scope, and can, for example, deactivate four cylinders out of eight, delivering the fuel economy of a V4 while cruising, but the power of a V8 on acceleration.
Tula Technology’s Dynamic Skip Fire program can dynamically, hence the name, drop out individual cylinders when they are not needed, for better fuel economy while cruising. When more power is needed, Dynamic Skip Fire reduces or eliminates the amount of “skipping,” for full power, as this video demonstrates…
Tula Technology’s innovation is primarily software-based, but would require engines to be equipped with individual cylinder deactivation hardware, and the only thing that makes it possible is the speed of modern computers. For example, in the average Chevy Tahoe V8 engine, cruising at 70 mph and 2000 rpm, each cylinder is fired 1,000 times per minute, or once every 60 ms. On full acceleration, perhaps 5,000 rpm, each spark plug fires every 24 ms, far too fast for conventional cylinder deactivation strategies. Faster processing can keep up and, the end result, it is hoped, could be up to 15% increase in fuel economy, without any sacrifice in power delivery.