Definition: 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 flamefront 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.
Examples: Honda has used a stratified charge design in many of its "lean burn" Civic models.
The Alternative Fuel Bible: Find Answers to Your Fuel & Vehicle Questions
The Alternative Fuel Bible: Find Answers to Your Fuel & Vehicle Questions