premium uleaded cars, recommented vs required

Does anyone know of a site that lists vehicles that either require or recommend premium unleaded fuel. I checked at KBB and Edmonds and for many vehicles it doesn't say. I am looking mainly at infinity G35's and equals.

It will say in the owners manual. I personally don't know of a resource online that keeps track of that info. Just curious, why do you want to know before hand? Are you concerned about cost of fuel? If so, it's not that much more per tank than the mid grade.

However, you can bet that the G35 and equivalent cars will require premium fuel.