I have just added Amsoil's Octane Boost to the preferred list for Motoring Alliance. Octane Boost increases the octane level up to 7 points, which reduces engine knock and helps fuel burn cleaner. Most will find using one-half a 12-ounce bottle provides the ideal performance increase. Residing in California I use half a bottle which boosts the octane level from 91, to approx. 94....my idle has smoothed out, and my MCS has notably more power! MA users save 15% off the displayed price by entering code # MA201201, upon checkout from Performance Improvers