I set these pages up several years ago to provide information about fuel "saving" devices, but have frequently been asked questions about other aspects of automotive technology. Here are a few pages about engines that may be of interest:

Performance "chipping" upgrades

General performance tuning

"Premium" fuels (Shell Optimax, etc)

Please do not ask me for any "insider information" on projects I may have worked on, nor any secret information on Bosch engine management systems. Confidentiality is confidentiality!