Ditto everthing Sport Pilot said. But would like to add that those above who reccomend the OS #8 have most likely not used it much in cold weather. The #8 is a COLDER plug than the OS A3. The #8 will last longer, especially in the summer, but the A3 is better in cold weather.
I also fly a lot in cold temps. Its been 20 to 30F here all week and I've flown a tank of fuel thru my new SPAD with .45 Super Tigre and a tank and a half thru my Avistar with Magnum .46 xls. at 29F. About 30min was all my fingers could stand in the thin gloves I had.