How is it that a 2.6 ounce bottle of 2 cycle oil can say it is good for 10, 16, 20, 32 and 50 to 1 ratios when mixed with one gallon of gasoline. I have a bottle of a pro mix formula that claims to do this. My gas trimmer requires a 32:1 ratio...add 4oz to one gallon. I went with the manual and added the 4 oz to one gallon of gas. Any ideas???