Thanks Richard! I won't have to find that link after all.<LOL>
Redhax, whatever sparkplug (and gasoline) works for you. Most modern cars have knock sensors which, when they detect knock, will "back off" the ignition timing to stop it. When the ignition timing is retarded, performance and mileage usually suffer a little. If your gas mileage increases with your 95 octane, I'd run that. It might take a few tankfuls of both types to get good baselines.
Something like a Scangage (sp?) might be able to tell you the ignition timing your computer is spplying.
If you go to 95 from 93 (no dea how that relates to US gasoline) the current sparkplug should be fine.
John