I have at least 30 cans of old two stroke mix oil I recently found in my dad's garage. This oil is probably from the early to mid 1980's. Do you guys think this should still be used? Does it go bad? Is the newer oil that much better that using the old oil is a poor choice? If using it is still an option, should I stick with the suggested ratio on the can? Please don't confuse using this old oil with being cheap, but I would hate to go recycle all of it. Thanks?