Only use what blade you need. Keeping the blade about an 1/8th of an inch above the stock when cutting reduces wear and tear on the blade and makes for a more accurate and smoother cut. The more blade you have exposed the more vibration you’ll see and the more non-cutting area of the blade makes contact with the wood, the more heat is produced.

If you don’t go by the 1/8″ rule, just set the blade so the gullet of the cutting tooth is a hair above the stock.