thats a very good question it leads me into something i have been testing in my car for a while now.
well you would think a plug is just a plug but i have found this not to be the case I have for the last 18 years sworn by NGK and damm fine they are but as time has marched on i wanted to find something new and went for the hks iridium plug again mighty fine, was happy with what i had but decided to do some sorcing of plugs called SPLITFIRE these are TRIPLE PLATINUM TIPPED and come with a 30 day money back gaurantee and also they claim 100,000 mls life I tried them and could feel better low down response, also i had my gas analizer on the car at the time and noticed the fuel mixture had improved by 1 whole percent it definatly burns better but i do also run a hks twin power as well
I have left them in the car and run 2 bar boost on them they are the nuts .
Having difficulty getting plugs, believe it or not. Can't find someone here (Aberdeen, UK) who stocks the ones Charlie suggested (NGK Laser Platinum PFR6A-11 4045) and need more info that NGK 7 (i.e. what is the rest of the code related to thread size etc). Any help? Cheers,