Does it help to use octane rated higher than your vehicle requires?

No.

* Added - Unless you are prepared to modify the tuning of your engine, the recommended octane rating is the best. Higher octanes do not provide more power, they simply burn slower. The higher the octane, the harder it is to ignite, which in most cases, will have no effect, but can make make the car harder to start. If you have an older car and have the equipment to adjust your vehicles system, using a higher octane fuel can result in higher gas mileage and more power. It requires that the spark timing be advanced to begin burning slightly sooner - and if a lower octane is then used with the same set-up, it can destroy the engine.