Toyota DI engine Toyota Motor Corp. has developed a 4-stroke, direct- injected(Di) gasoline engine. In conjunction with the new DI engine is another crucial item: a production-ready 3-way exhaust catalyst capable of oxidizing the oxides of nitrogen (NOX)-rich exhaust inherent to lean-burn engines The new engine, designated D-4 by Toyota, is a 2L DOHC inline 4-cyl Compression ratio is 10: 1, and the engine operates efficiently on regular unleaded gasoline The D-4 incorporates a highly optimized combustion chamber: The piston crowns are fitted with a lipped, cup-like formation that focuses the injected air/fuel mixture tightly around the spark plug for maximum burn Intake air is drawn through helical ports that create a high degree of horizontal swirl which Toyota says combines with the lipped combustion chamber to not only maintain highly stable combustion-a quintessential problem for lean burners--but also to stratify the air/fuel mixtureToyota DI engine Toyota Motor Corp. has developed a 4-stroke, direct￾injected (DI) gasoline engine. In conjunction with the new DI engine is another crucial item: a production-ready 3-way exhaust catalyst capable of oxidizing the oxides of nitrogen (NOX )-rich exhaust inherent to lean-burn engines. The new engine, designated D-4 by Toyota, is a 2L DOHC inline 4-cyl. Compression ratio is 10:1, and the engine operates efficiently on regular unleaded gasoline. The D-4 incorporates a highly optimized combustion chamber: The piston crowns are fitted with a lipped, cup-like formation that focuses the injected air/fuel mixture tightly around the spark plug for maximum burn. Intake air is drawn through helical ports that create a high degree of horizontal swirl, which Toyota says combines with the lipped combustion chamber to not only maintain highly stable combustion—a quintessential problem for lean￾burners—but also to stratify the air/fuel mixture