You can add it directly to your oil to help remove sludge and varnish inside the motor - add it a few hundred miles before your next oil change. I've found that adding a quart of ATF works just as well.

You can add it to your fuel tank to help clean injectors also.

When in doubt, read the instructions on the can.

95 Montero SR
3.8 MIVEC, Advance headers, 2 1/2" exhaust, Magnaflow muffler, OME shocks & rear springs, 2" body lift, 3" tank lift, 4.90s, TRE front locker, factory rear locker, Roger Brown Rock Sliderz, 315/75r16 (35") tires, Sport big brakes