Unless your warranty requires premium fuel you're also wasting money on it over regular. Reason being premium fuel stays in the stations tanks longer and loses octane over time. And, if you can run regular in your engine without knocking, premium fuel has no advantage even if it were fresh. http://www.consumerenergycenter.org/transportation/consumer_tips/regular_vs_premium.html http://www.scientificamerican.com/article.cfm?id=fact-or-fiction-premium-g