Join Date: Jan 2000
Location: madison, AL, usa
My experience is that keeping the plugs fresh and good condition will result in good service. When I was racing, there were some brands that performed better than others (lower ET, longer life, etc), but changing camshaft, heads, etc would lead to another brand that ran better. So, my recommendation is that unless you are able to actually measure performance differences in brand to brand or design to design, just simply plan on making them a part of your upkeep program.
On my early 289 stuff, I normally found that the Nippondenso, that looked suspiciously like the Accel plugs worked best. I also used Bosch. Motorcraft, Autolite/Fram, and AC performed satisfactorily. Champion typically did not fair as well. But brand to brand differences can also be based in the heat ranges being slightly different too. All sorts of things can feed in to the equation. On my drivers I typically change out once a year. On project stuff, it may be once every 6mos or so. On my race car I would start the season with a fresh set and oil. Then about mid season, when ET's began to drop off I would put in a fresh set, and change the oil again.
Fresh and new is the sure bet.
a plug for a 4 cylinder versus 8 cylinder! The cylinders do not how many neighbors they have.
When platinum plugs first came out (circa '84), we would get returned sets all the time. we always attributed the issues to non adjustable gap and heat range problems. we took back more than few for sure.
as they began coming more and more as original equipment, the problems began going away as the engineers (auto company and spark plug company)began getting a better handle on the designs and coverage.
Last edited by buddy rawls; 11-04-2009 at 10:35 AM.