Thoughts on octane ratings
There was a massive thread on this somewhere on the forum, most of which I read through at one point. :crazy:
The owners manual of the Aussie delivered 300C suggests "designed to provide optimal..blah...blah...using high quality gasoline with a minimum research octane rating of 95." It goes on to say that we can use 91RON if 95RON is unavailable but performance will probably suffer.
I think the summary position on the forum was, in the US they recommend the mid-rated fuel, ie. RON89. In Australia we have 3 variants as well, which you point out are all quoted above the top quality US fuel. It has been suggested that this is due to a slightly different formula in the US or regulation about the number used to represent the RON and in fact it is the same stuff at the same grades but the number reduced by about 2 in each instance. Therefore, I'm using "mid-strength" 95RON (Premium but not 97 Optimax etc) in my 300C Hemi.