Interesting fuel octain discrepancy I found.

This isn't only a Triumph thing. In a former life I used to work for a Toyota dealership. One thing I found amusing was that the Avalon had 3 trim levels. All 3 had the same exact engine, power numbers etc. Despite that the two lower trim levels called for 87 octane while the XLS said it needed 91. I think it's somewhat arbitrary but for performance engines like on the Rocket I feed it 91 whenever I can and stick to Chevron as they use TOP TIER gas which I've seen recommended regularly for high performance engines.

"In Brazil, I stick to 87-octane regular gas (93 RON). Petrobras' premium fuel is 95 octane (102 RON), and likely due to the fueling map, my bike would sputter or stall at idle whenever I used it. Even the Triumph dealer recommended sticking to regular gas