Fuel Additives - Octane Booster - Safe or Not?

[banpei]

Just using 98 octane. I don't see a point in using an additive if your engine is healthy. In my opinion, most of these additives are snake oil anyway and, if they do work, they only add benefit within a certain set of boundaries. The 4A-GE was made as a generic performance engine to run on lower grades of (unleaded) fuel, so I'm not convinced any of the additives will do much.