Hmmm... if I remember correctly octane has to do with the ignition point of the fuel when pressurized in the cylinder; used in high compression, high performance engines where "dieseling" would be a problem - like my Triumph Trophy:), but not my minivan! :( http://www.ftc.gov/bcp/conline/pubs/autos/octane.htm http://www.chevron.com/prodserv/api_octane.html http://www.encyclopedia.com/articles/09474.html Not sure it necessarily leads to the benefits you listed. Norman > > A UK 'imperial' gallon is more than a US gallon, and, I think you'll find, ours > is a higher octane (better quality, cleaner burn, less damage, better mpg) > > > Garry >