If a manufacture specs a particular octane for their engine, you should use it. I get sick of all the people that think they know better than the very engineers that created the engine. It also boggles my mind that the FJ owners get defensive about the premium label, if you spend 25k for a new truck, use what is recommended. Its not a surprise that premium is recommended, that is what the ecu was mapped to run, there is a range of acceptable operation, but what do you want? just ok? or whats best for the truck. Fact is, the premium is what helped the FJ get its extra little bits of power specs (marketing). To Fj owners its a negative, and they cant accept that. Oh well, we all get defensive about things we put $ into, so its ok