In my opinion Denso plugs are the best. Toyota and Lexus use them as standard and I have never known one to go wrong. NGK are pretty good too. Avoid Champoin as they are tiolet, I won't even use them in my lawnmower. Splitfire (if you can sill get them) are a waste of time and are rubbish.
I don't think I have ever gapped a set of plugs, they just go in.
Cleaning plug tips is only necessary if you have had a problemand they are coaked up (I normally just replace) or if your too tight to replace them every 20'000 miles. you can clean and regap quality plugs and get another 20'000 out of them (unless you have platinium or iridium plugs, is won't work with them).
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