From the spark plug thread that I started in forced induction, I learnt that the gap depends on the boost you are running, for stock the gap is 1.1mm if you are running 12psi or above 0.8 is recomended, as for plugs there is no perfomance gain to be gained from any but the life of the plug is greatly increased with platinum (80,000ks) and better still with iridium (100,000-160,000ks) compared to coppers which are recomended to change at 5,000ks although some say they last to 10,000 upto 40,000, if you can change them yourself go the coppers recomended above, I am using iridiums and they have been in there for 60,000ks now and still good, I know because I keep pulling them out when something else stuffs up. Price wise they arent worth it really, I have been told that they are good in motors where changing the plugs is an absolute pain.
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