Semi slick tires generally refer to tires that have a design that somewhat replicates the slick racing tires that dominate on race tracks. The slick smooth tire tread and construction is thought to prioritise grip over the tread patterns typically found on tires. A major selling point of the semi slick tire is that it would often yield a road legal tire as opposed to the truly slick tires found in professional racing . This yields a much more convenient setup as it allows the car to be driven to a racing event and then used in that event without requiring a tire change.
Generally such tires while offering great dry grip performance, they are prone to aqua planing in wet and dry conditions. They also tend to have a severely limited lifespan as what limited tread they have tends to wear out pretty quickly. The rubber compounds are also softer and tend to undergo a process called heat cycling that leads to them heating up and then cooling down in a way that changes the chemical structure of the rubber. This change can start to make the tires lose grip performance quite quickly.
It should be noted that semi slick is a general description of a tire without a hard definition and manufacturers do not always use the term to refer to their own tires. Semi slick tire models are:
Note: The term road legal used in this article doesn't imply that these tires are legal in all jurisdictions.