I use 89 octane and Spyder seems to run better than on 91 Premium.
I also every 3rd fill-up add the best kept secret in history, about 1/4 cup Marvel Mystery Oil!!
The spyder runs much better after that is added. I was once told by an engine rebuilder that Marvel Mystery
Oil is the best fuel additive in the industry. I use it in my cars and it really makes a difference.