I bought a new Toro (20332)self-propelled mower with the 6.75 "torque" motor. I ran the break-in oil (Brigs 30) for probably 3 hours of usage. Then I switched out to M1 0W-30. The problem was that it would puff an embarassing cloud of smoke on start up with that 0-30 oil. So, I switched to good old cheap Wal Mart synthetic, 10W-30 and the problem went away. Do you guys think that it puffed smoke becasue the motor wasn't yet broken in, or was the oil indeed too thin? What I think is that these motors are made with loose tolerances and they need thick oil, if that makes sense.