I also do the same with my gas- my complete distrust of the oiler (and paranoia) have led me premix 50:1 for all my bikes. I used to use 40:1, in addition to the oiler, but that is overkill, even for me. I think 50:1 (2.56oz per gallon) using high quality(yamalube) oil would prevent piston seizure in the event of a total oiler failure. In reality, 4-5 ounces of oil per 2 gallons is probably the best cheap insurance you can use. Also keep in mind that autolube oil is differnet than premix oil.