I ran my Rst on regular unleaded for 3 years problem free. I then decided one day to put Shell Optimax in ( Called V-Power at the time ) and it ran and idled fine but what I did notice was the running temperature was a lot hotter and it DID MESS my plugs up.

I was lead to beleive that 98 Ron burns at a hotter temperature and this was the cause of my problem.

I brimmed up with normal regular 95 Ron unleaded and changed the plugs and had no further issue.

Thats my experience with it. I do use it in my Cossie now though