Patent ID: 7822531

Claim:
A method of reducing emissions and improving knock-tolerance in an engine, comprising: providing air, including exhaust gas present at levels greater than 20% by total air mass; introducing said air, including said exhaust gas, into a combustion chamber having a volume including a piston and a cylinder head; injecting a first amount of fuel in a range of 60% to 95% by weight of a total fuel mass directly into said combustion chamber, when said piston is moving away from said cylinder head; injecting a second amount of fuel in the range of 5% to 40% by weight of the total fuel mass directly into said combustion chamber, when said piston is moving towards said cylinder head; and igniting said first and second amounts of fuel, wherein the ratio of said air, including said exhaust gas, to said first and second amounts of fuel is maintained in a range from 14.0:1 to 15.0:1.