The A3 is a tad hotter than the #8 . OS puts them in LA's and smaller engines. They are cheaper and seem to last just as long as the #8. I like the idea that in some small way I buy american made. My only plug I now use is FOX RCLONG the idle bar plug. Works great in every size and brand I own. Maybe the top end might be down a few hundred RPM. But I'm not racing. If the idle bar has saved me from a few deadsticks (praise the lord) HE HE HE