Gasoline direct injection systems

Gasoline direct injection (GDI) looks somewhat like the 42 volts or stop-start systems sagas: even if these technologies show some obvious benefits, their production has been delayed for various reasons or has met some setbacks. However, gasoline direct injection is far from being a new concept since the first applications appeared in Germany in 1937 on aircraft engines and in 1952 on automotive engines.

After several attempts, this technology seems now quite mature enough for mass production, either on reliability, fuel economy, CO₂ and pollutants emissions or on range of operation standpoints. Up to now, the Volkswagen Group offers the most extensive choice of direct injection engines, but Lexus, BMW and Mercedes present rather more imaginative or advanced ways such as dual injectors or piezoelectric technologies. Due to the technical and thermodynamical reasons exposed below, it can be safely assumed that GDI is intrinsically an essential part of up to date and future downsized and turbocharged spark ignition engines. Although higher production costs hinder at the moment a broader marketing, almost all the OEMs have gasoline direct injection engines in development.

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• Page 1 : Summary
• Page 2 : Gasoline Direct Injection (GDI) history
• Page 3 : Direct injection, homogenous - 1/2
• Page 4 : Direct injection, homogenous - 2/2
• Page 5 : Direct injection, stratified charge, wall guided - 1/2
• Page 6 : Direct injection, stratified charge, wall guided - 2/2
• Page 7 : Lexus dual injection : multiport and direct - 1/2
• Page 8 : Lexus dual injection : multiport and direct - 2/2
• Page 9 : Direct injection, spray-guided: presentation
• Page 10 : Direct injection, spray-guided : principle and injection strategies
• Page 11 : Direct injection, spray-guided: injectors
• Page 12 : Direct injection, spray-guided: fuel system
• Page 13 : Compared advantages of the various direct injection concepts