Keep your intake valves clear of harmful buildup. Reduces problems such as hard starting, rough idling, poor acceleration, lean surging, engine run-on, all caused by excessive build-ups in deposits on the intake valves and combustion chamber. Helps lower fuel consumption and exhaust emission. Here is a test we performed - an unscientific test, but a test of the effectiveness of the solvents of Valve Clean on fuel/oil deposits: