Right - just like there are different kinds of metals, different kinds of tires, different kinds of glues, diffefent kinds of spark plugs - they are all different, that's all. There is a reason to use higher octane gasoline, just like there is a reason to use lower octane gasoline. Cars that run higher inlet pressures and higher inlet temperatures need higher octane gas - period. The DeLorean is not one of these cars. Higher octane gasoline is harder to ignite than low octane. That is what octane measures. The reason you might want gasoline that is harder to burn is because you want the gasoline to burn at a specific time - when the spark plug fires - not when the piston is halfway through the compression stroke. Detonation at this time (known as knocking, pinging or pinking across the pond) damages piston crowns, rings, wrist pins, connecting rods and bearing journals. Using a higher octane than recommended for the application not only costs more at the pump, but it will usually lead to poorer ignition characteristics, which means the fuel will not burn as completely or as efficiently as it should. This means less power and higher emissions. -- Mike -------------- Original message from "Tom Niemczewski" <tomciodmc@xxxxxxxxxxxxxx>: -------------- > Dan > > One reason could be because oil companies don't really want you to know > about it. Most people don't have a clue what "octane" is. People don't care. > Hard to give a simple and definitive answer. > Anyway, why are there different grades of gas? Do you really believe that > higher octane is somehow better? It is different, that's all. Because there > are different cars out there with different engines and different grades are > available for them. Not better, just different. > > Tom Niemczewski > vin 6149 (in Poland!) > tomciodmc@xxxxxxxxxxxxxx > www.deloreana.com [Non-text portions of this message have been removed] To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/