Letter Re: Question on Two Cycle Oil Mixing Ratios

Dear Mr. Rawles,
Perhaps you could help me understand the mixing ratios for two stroke oil.
I remember buying the old Homelite oil, you could either buy it in a can to mix with one gallon of gas or a can to mix with two gallons of gas.
Most of the new two stroke oils I have seen recently state that they are 50:1.
Is this mixture acceptable for my old Homelite Super XL chainsaw and other two stroke equipment?
The rep at the Stihl store by us said that the new oils are so much better formulated than the old oils, that 50:1 is good for all two stroke equipment–old and new. Does he know what he is talking about? – Mark G.

JWR Replies: While it is true that some of the pre-1990 manufacturers’ manuals called out a 32:1 or even 24:1 mixing ratio, with modern name-brand mixing oil, there is no problem using a 50:1 ratio in just about all two cycle chainsaws and other two cycle power tools that are marked 24:1 or 32:1 (such as leaf blowers, weed trimmers, ice augers, et cetera). The modern mixing oils provide plenty of lubrication at a 50:1 ratio. You can use more oil if you’d like, but it would be a waste of oil, and will also produce more smoke.

OBTW, I discovered that there is an interesting thread of conversation on this topic over at The Arborist Site Forums.