My Craftsman 21 cc/15" cut is going on 21 years of service and my Homelite blower is going on 12 years. I bought my two stroke ;LawnBoy in 1996 and it still starts first pull. I always mixed my two stroke oil out of a qt. container and never used Stihl, Echo or Lawnboy oil. I actually used Amoco oil for the first 10 years, till I couldn't get it any longer. I use a TC oil and run it rich, 20;1 OR 32;1, never any less regardless of what the manufacture says. I run them hard, full throttle and it apparently works, because they all still run good.