According to my oil man two stroke oil is basically unregulated as far as testing for say military specifactions or most any other testing, most engine manufacturers will recommend a certain brand or quality of oil for their engines, four stroke oil is tested and regulated, the numbers on the bottles say its good and meets a certain criteria, thats stamped on the bottle, say a military spec or an API Service of say SM/SL or CF/SM or somthing like that, if you have a four stroke engine on your 4 wheeler or motorcycle, car or pickup then the owners manual will have what spec of oil is required for each engine, its a testing standard used to make sure the oil is good enough to not cause engine problems or engine failures, the newer the engines the higher the standards are required for the oil you put in the vehicle, now theres gas and also diesel grades of oils and also the specifacations for each, gas engine oils are not good enough to run in diesel engines without causing damage to them.
Now two stroke oils have no certifications or compliance they need to meet so its up to the engine manufacturer to have thier own set of standards for their two cycle engines, now stihl and dolmar and echo and all the rest don't manufacture the two stroke oils but they each put out the specs their engines require and the oil companies make it to each engine manufacturers specifacions and when you go into a stihl dealer and buy the orange stihl two stoke oil from them then that formulation is for all stihl engines and won't cause harm or damage to thier engines. Now is there a lot of difference between all the oils, some claim theres a difference between air cooled and water cooled, yes partly right, the basic difference is the engines manufacurers requirement that their engine went through and what it needed to perform right, the answer of air cooled engines run hotter is true but it still gets down to the fact not all two stroke engines are the same. A mercury outboard and a johnson will both claim thier engines take a different oil specifacation than the other as will a polaris four wheeler thats two stroke and a stihl chainsaw will also be different, now is it a big deal, probably not, I've mixed and matched oils over the years and my stuffs still runs but if your buying new and you want warrenty and theres a problem the first thing they'll ask is what kind of oil did you use, just like the four stroke motors will for warrenty purposes to make sure you adhered to thier engine requirements, as they say been there done that and learned a long time ago until its off warrenty just use whats recommended and after the warrentys off, well then your on your own anyway and use whatever you want to. When you go to the fleet store and get a gallon of oil mix, thier formula is basically an average of the needs across the largest spectum of two stroke engines out there or its a left over in a batch some engine manufacturer like stihl or johnson or whoever didn't take the full quantity of and they just bottled it for whoever else instead.
I demoed a dolmar saw and the dealer gave me a few bottles of synthitic oil mix and told me to run that in the dolmar saw instead of the stihl mix I'd been using in all my stihl saws for years. Is there a big difference, all my dealer told me was the engine manufacuturer thinks so and so thats what I used in that saw. I'm not saying you need to adhere to it by any means but most people don't even know that theres not any independant testing done on two stroke oils in the first place, all the tc3 or whatever pennzoil uses is an addative and also a selling point thats its supposed to be better, is it, who knows its only thier claim and not the goverenments or militarys so whos to argue one way or another. Its just some information that was passed onto me over the years and use it however you'd like.
