Yes, it would cost too much for gas companies to develop additives like this for your gas so buying after market stuff will help. Gas companies care about competing with the guy across the street, not making your can run smoother. Is it necessary? Probably not, but they do what the advertize if you buy a time tested one. I like straight Techron for cleaning and UCL for every tank upper cylinder lube. Lube Control is another real popular one, but the reason I use UCL is because it's cheap by the gallon and you can buy it local, and I've had great results.