As of August 2015, good gas tank cleaning products for automobiles include Chevron 65740 Techron Concentrate Plus, Red Line Complete and Royal Purple Max-Clean. Each averages a rating of at least 4.5 stars in Amazon.com's five-star user rating system.
Reviewers say that Techron Concentrate Plus solves fuel line problems quickly and makes cars run more smoothly. It resolves certain problems that garage mechanics say require costly repairs. Positive comments mention that Red Line increases gas mileage and helps cars be more responsive. It is a good value.
Reviews for Royal Purple fuel system cleaner state that it improves misfires and throttle response. The product lasts longer than other brands.