2010 Mini Cooper Mileage

High octane = slow burn rate. The cars that require premium were designed to be most efficient / make more power based on the slow burn rate of premium. longer stronger boom on top of piston instead of small firecracker pop with reg. Make sense? Your mileage may be better with reg is driven very sensibly as long as not under load and having to retard timing for spark knock. I’m not a technician what do I know?