Some of this is biased but its good info.
Shell
http://www.nealswheals.com/NealsVisitors//PDFs/Gasoline_Media_Presentation_FINAL.pdf
Chevron
http://fileserver.urimarketing.com/LU/CourseCatalog/Gasoline_Fuel_Additives.pdf
General Motors
http://www.gmfleet.com/pdf/TechTip_0905_TopTierGasoline.pdf
US EPA Detergency Question & Answer
http://www.epa.gov/oms/regs/fuels/additive/detergnt/gdacq-a2.pdf
Federal Register touching on Lowest Additive Concentrate (LAC) Fuels
http://www.epa.gov/oms/regs/fuels/additive/ffaminor.txt
Shell
http://www.nealswheals.com/NealsVisitors//PDFs/Gasoline_Media_Presentation_FINAL.pdf
Chevron
http://fileserver.urimarketing.com/LU/CourseCatalog/Gasoline_Fuel_Additives.pdf
General Motors
http://www.gmfleet.com/pdf/TechTip_0905_TopTierGasoline.pdf
US EPA Detergency Question & Answer
http://www.epa.gov/oms/regs/fuels/additive/detergnt/gdacq-a2.pdf
Federal Register touching on Lowest Additive Concentrate (LAC) Fuels
http://www.epa.gov/oms/regs/fuels/additive/ffaminor.txt