The vast majority of passenger car tires are non-directional, meaning the tread pattern is the same regardless of which direction the tire is mounted on the rim. Some performance tires, however, have a specific tread pattern that is intended to face in a certain direction for optimal performance. Mounting these directional tires in reverse can have adverse effects on handling, negating the benefit of their directional tread design; putting directional tires on your car carries a number of advantages and disadvantages that must be taken into account before making a decision.
Directional tires tend to be high-performance tires, made of performance-oriented rubber compounds, driving up entry costs. The performance-oriented nature of the tires that tend to carry directional treads is not an inherent trait to the tire design, though, so while the costs of directional tires does tend to be higher than non-directional tires, the entry cost price difference could change.
Directional tires feature a tread pattern that maximizes the grip of the tire based on acceleration and braking forces and how they effect each tread of the tire. Directional tires' optimization of the forces from starting, stopping and cornering lend this style of tire a clear advantage in handling over a non-directional tire, which is built for utility.
Directional tires usually feature a deep groove in the center of the tread pattern; this groove is designed to maintain maximum tire contact area with the ground, while treading away water or snow. The advantage of having this center-line directional tread pattern helps prevent loss of traction in adverse weather conditions, particularly dangerous hydroplaning. A non-directional tire tread pattern can not possibly address these issues at the same level as a directional tire, giving the adverse weather advantage to the directional tire tread patterns.
Directional tires must be mounted in the direction of the arrow on the tire's sidewall, or else the tire's advantage is negated. This presents an inherent disadvantage of directional tires; directional tires are limited in terms of tire rotation patterns. A non-directional tire can be rotated front to back and cross-rotated, but a directional tire can only be rotated front to back, with cross-rotating ruled out. This decreases the life-span of a directional tire compared with a non-directional tire of equivalent construction quality.
