Get a grip
Winter tire choice still includes the option of studded versions. I dread debating the topic, but there are at least three inarguable facts about studded tires: They increase road wear. Any slight advantage is only on rare glare ice conditions. Their grip is inferior to any non-studded tire on wet or dry roads.
Use of lighter studs comprised of aluminum alloy as opposed to tungsten purport to assuage road wear, but fall short of the road maintenance savings that would result from an all-out stud ban.
Reader opinion ranges from “let’s get rid of them” to “I can’t get up my driveway without them.” I believe that those supporting the latter sentiment have not given modern, non-studded, all-season or winter-specific tires a fair chance, but closed minds change slowly if ever.
The statistical information I find from state transportation departments, tire manufacturers and other entities is extensive. The variables of road surface, temperature, vehicle and tire type generate voluminous results to consider. All of those stats and studies, however, lend credence to the theory that added safety derived from winter use of studded tires is questionable.
It is absolutely true that studded tires have less surface adhesion, imperative for stopping and turning, than even the cheapest non-studded tires on wet or dry roads. I find it puzzling that alleged safety-driven stud users are willing to drive on tires that are inherently safety-deficient over 95 percent of the time during our winters.
Studs do have a slight traction advantage on the clear ice we see on our roads less than 5 percent of the time in an average winter. Not only is that advantage slight when compared to most quality winter-specific or siped tires, but actually nil when challenged by the best ones. Again, vehicles equipped with studded tires have greater stopping distances and less cornering grip than they would with any non-studded tire absent ice.
The slight gap in glare-ice grip of non-studded tires can be closed through added vigilance, reduced speed and skillful vehicle operation. I notice that the use of studs increases driving aggression for some, as I view long stud streaks in the ice at intersections from harsh stops and starts. I also note that I am able to stop and start at these same icy locations without skidding or spinning my stud-free tires.
I never see police vehicles with studded tires — even when the typical cruisers were rear-wheel-drive Crown Victorias. I think those agencies are sympathetic with the huge costs of road wear associated with studs, and police officers appreciate the dry/wet road handling and high-speed stability of non-studded rubber.
Hydroplaning is another consideration on wet roadways, and tread depth is its best combatant. Lift-by-water also depends on factors like vehicle weight, speed, tire width and water depth, but the importance of tread grooves is paramount. New tires are typically made with 10-12/32nds of an inch of tread depth, and are legal to use down to 2/32nds. I personally discard tires when they reach around 4/32nds of an inch of remaining tread. Even at that point, the propensity for hydroplaning is much greater than when the tires were new.
As tires wear, it is up to the driver to realize the state of their equipment; a conscientious driver should use additional care and less speed during downpours when riding on half-worn tires over a new ones.
Readers may contact Bill Love via e-mail at precisiondriving@spokesman.com.
