Performance air filters are tested on a dyno to find out whether they really increase engine power or mostly change sound and ...

Air filters are one of the easiest and quickest components to swap out for an aftermarket part, and plenty of companies claim their design will increase horsepower, torque, and improve acceleration.

While I've never been the type of person to be particularly stressed about getting every possible power gain out of my car (when I owned a car), I've always been skeptical that a performance air ...