Funny how fate works... I was just using my favorite trimmer yesterday and had to shut it off to fix things 3 times in 20 minutes . I said to myself "this is the last year I put up with this wretched junk." It's a Troy-Bilt $99 Walmart special from like 4 years ago. I decided to start saving for a Stihl 4 stroke. I went to visit some distant family members later on. I was griping about my trimmer and said I am going to start saving for a Stihl. His eyebrow raised and said to follow him to the garage. Sure enough, he had one. So of course I have to play with it. It was a 2-cycle, but was SWEET! Well, one thing led to another and he was saying he wanted a 4 stroke as well. This was his incentive to upgrade. He just gave me his Stihl FS 111 R trimmer. No clue on age, maintenance history, or hours used (I didn't think to ask, I was too mesmerized at the situation. I will the next time I see him). I already downloaded the instruction manual and will read over it when I get time, but any pointers in the meantime? Just by skimming the manual, it calls for 89 octane (weird ) and a 50:1 mix. Are Stihl trimmers picky about anything? Do I need to buy premium 2-cycle oil or just the 99 cent specials from Ace? And is the 89 octane really a requirement? I don't mind even paying for 91 if it prefers it, I'm just wondering how to truly get 89+ octane in just a gallon of gas in a can (without spending extra and filling my car with 5+ gallons beforehand). The pumps can take up to 5 gallons before dispensing the correct octane. Regardless, any input is appreciated!