Lean burn

A lean-burn engine (also lean burn ) is an internal combustion engine, the air / fuel mixture is kept in the lean region. Lean means that more combustion air is present, as required for the stoichiometric combustion of the fuel in the cylinder ( lambda> 1). Of excess air means that the combustion temperature is reduced and in this way both the efficiency and the concentration of nitrogen oxides in the exhaust gas.

During lean-burn engine is used partly direct to store the fuel in spark plugs still in near ignitable concentration ( stratified charge ).