The development in cheaper slick technology has affected the development of tyres for racing series other than drag racing as well. When other forms of auto racing similarly instituted classes which require DOT approved street tyres, some manufacturers similarly began to market tyres which superficially resembled their high performance street tyres, but with the least tread pattern permissible and with very soft, sticky rubber, intended specifically for competition because the soft tread would wear too quickly for street use. These became known as R compound tyres. With additional years of progress, this class of tyre has followed its own line of development, to the point where they have little in common with true street tyres of the same brand. This has led to new classes of racing which require not only DOT approval, but also a minimum treadwear rating, in an effort to eliminate the R compound tyres from competition and require "true" street tyres.
