Spark Plugs on Their Way Out? Here is What Might Replace Them

When you boil it down, improving the average fuel economy is super simple: Burn less fuel in the cylinder when cruising. Toward that end, engine developers have toiled to make lean mixtures work since way before Chrysler's Electronic Lean-Burn System of the mid-'70s. But getting such mixtures to ignite via the spark plug (in engines since the Model T) has been problematic. Now Torrance, California, startup Transient Plasma Systems is proposing a low-temperature plasma ignition system that it claims can replace the spark plug.

How Do Traditional Spark Plugs Work?

Here's how traditional spark plugs work: Energy generated by a coil builds across the spark plug's air gap until the energy potential ionizes gases in the gap. This causes the gases to become conductive, resulting in a current spike and a momentary flash of hot plasma—like a tiny lightning bolt. A minuscule percentage of the energy used to create that spark ends up thermally igniting the fuel mixture, which then must propagate throughout the cylinder.

How Does a Transient Plasma System Differ?

TPS proposes employing a different kind of plasma to initiate combustion in a…