Every week, Exhaust Notes will pick out an industry, technical or obscure term from the automotive world and give you the lowdown on what it means and how it’s used. Already know the answer? Congratulations, you’re ahead of the game.

If you’d like an explanation of an automotive term, e-mail us at autosblog@live.com

This week’s term: Drive-by-wire.

If "drive-by-wire" sounds familiar, it may be because the term was mentioned in conjunction with the floor-mat-related Toyota recall. You may remember the post mentioning that certain foreign automakers -- such as Audi -- employ a system that would eliminate unintended acceleration via an electronic system that overrides the accelerator when both it and the brake are deployed simultaneously. Such a system is possible when the acceleration and braking are controlled not mechanically but "by wire," i.e. electronically.

That's the crux of the definition: Drive-by-wire is a sort of catch-all term that means some or all of the throttle, brake and steering are controlled electronically. Alternatively, if only one of these systems is employed, you may see vehicles referred to as brake-by-wire, steer-by-wire, etc.

This technology could actually be used to control a car by joystick (as seen in some concept cars), but even though drive-by-wire technology replaces traditional mechanical and hydraulic control systems, mass-market vehicles still use it in conjunction with the driver-car interfaces (such as a brake pedal or steering wheel) associated with the mechanical systems.

A benefit of drive-by-wire is reduced weight and less vehicle wear-and-tear over time -- the traditional systems such as the master cylinder, steering column, rack-and-pinion gear, and various hydraulic lines are heavy and mechanically complex -- though some worry that software glitches or electronic failure could result in accidents. It should be noted, though, that airplanes have been using the technology (called, appropriately, fly-by-wire) for more than a decade.