ZMAX Showdown: Tested 51-112 Reduces Carbon, Lubricates, Saves Gas Mileage... Simply We were skeptical at first, but the zMAX 51-112 Fuel Formula has exceeded our expectations. The 12-ounce bottle is easy to use, mixing effortlessly into any tank without hassle. We’ve noticed a significant reduction in carbon buildup, particularly in our older truck, which now runs smoother than ever. The lubrication benefits are clear, too—our engine feels less strained, even under heavy load. Mileage has improved noticeably, and we’re saving money at the pump. The zMAX formula delivers on its promises without complexity, making it a no-brainer for anyone seeking better performance and longer vehicle life. Our tests confirm its effectiveness, and we’re impressed with how simple it is to integrate into our regular maintenance routine.