The stratified charge engine is a type of internal-combustion engine which runs on gasoline. It is very much similar to the Diesel cycle. The name refers to the layering of the charge inside the cylinder. The stratified charge engine is designed to reduce the emissions from the engine cylinder without the use of exhaust gas recirculation systems, which is also known as the EGR or catalytic converters. Stratified charge combustion engines utilize a method of distributing fuel that successively builds layers of fuel in the combustion chamber. The initial charge of fuel is directly injected into a small concentrated area of the combustion chamber where it ignites quickly. As the combustion process continues, it travels across the top of the piston to a lean area of the chamber, where cooler temperatures reduce the formation of harmful NOx emissions. Subsequent additional small injections of fuel can be introduced to propagate the flame front and manage piston knock. This arrangement works well in slow constant speed applications, but has proven difficult to manage across the wide range of speed and load incurred in automotive uses.