Patent ID: 6125801
Filing Date: 2000-10-03
Classification: F01L,F02B,F02D,Y02T

Abstract:
A method of improving the fuel economy and reducing the tailpipe emissions of spark-ignition internal-combustion engines having a displacement volume, a combustion chamber volume, means for adjusting the compression ratio comprising an adjustment mechanism to vary the combustion chamber volume, an intake and exhaust valve overlap period, and a fuel to air equivalence ratio,a first engine setting having a first compression ratio position, a first valve overlap period, and a first fuel to air equivalence ratio, wherein the engine has an adjustable fuel to air equivalence ratio, and the first compression ratio position is below the knock limit of the engine at the first engine setting, having the steps of,increasing the compression ratio from the first position to a second position, and reducing the fuel to air equivalence ratio from the first ratio to a second ratio,whereby increasing the compression ratio from the first ratio to the second ratio, and reducing the to fuel to air equivalence ratio from the first ratio to the second ratio prevents detrimental engine knock and increases engine efficiency.