This blog originally appeared in HWT’s sister publication Commercial Carrier Journal and was provided by Joe Puff, vice president of truck technology and maintenance, NationaLease.
Selecting the right tire tread design for an application can have as profound an effect on tire cost as proper inflation pressure. Much like setting one standard tire pressure for all trucks, fleet managers often set one standard tread design to work for all its trucks.
Of course you should standardize whenever possible, but standardization needs to be supported by facts. It is not wise to choose one tread design for all trucks just because, “it’s easy and we’ve always done it this way.” There is too much risk if the wrong tread is selected for a given application so do your homework instead of guessing which tread is right for a truck.
Selecting a tread design starts with understanding the terrain, vehicle duty requirements, climate, speed, and the vehicle’s operational environment.
Here are several factors that should be considered when making the tread design choice:
• City, regional, or line haul application
• Desired rolling resistance for fuel efficiency
• Weight, traction, and miles operated
• Weather conditions — extreme temperatures both high and low
• Price vs life cycle cost
• High or low scrub application
• Products being hauled — bulk liquid or solid load
Tread selection is further impacted by regional pavement differences and road conditions. Some roads have high silica content which can scrub rubber off more aggressively. The percent of time a truck operates on snow and ice can play a significant role in tread selection. So when making that decision, all these factors should be considered and weighed against the fleet’s risk tolerance for each.
It is best to make tread design selections on a truck-by-truck, application-by-application basis.
It is easier for a fleet manager to standardize tread designs when all vehicles in the fleet have similar applications and operate in similar condition. However, the right selection can be very difficult for fleets that have heterogeneous applications. The challenge is trying to balance the optimal tire selection with standardization. The more tread designs a fleet uses the greater the complexity in managing the tire program.
Heterogeneous fleets must also balance the cost of managing the complexity, the fact that there is less opportunity to swap tires, greater casing management time, and capital invested in stocking a larger inventory of tire tread designs.
There is a lot to consider when weighing ease of tire management and the optimal tire efficiency. It is much easier to opt for the simpler less complicated standardized tread designs, but you need to know the cost. If tire costs could be lowered 10 percent with proper tread selection, would it be worth the extra effort to manage the more complex tire program that comes from using more than one tread design?
In years past we relied on some basic tread design fundamentals. Things like a closed shoulder outperformed an open shoulder in scrub applications, or an open shoulder had better traction than a closed shoulder. Or deep wide tread groves dispersed more water and provided better wet traction. Today, with new technology in compounds and tread designs that is not always true.
As mentioned in the article Selecting the Right Tire, tire manufactures have data books that can help a fleet find the tire and tread design that best suits their tolerance for each factor. In general I find these data books to be pretty accurate when comparing a tire manufacturer’s product line up with the vehicle application. However, comparing one manufacturer to another manufacturer is much more complicated. This requires good accurate fleet testing.
There can be a great cost savings opportunity when selecting tires for new vehicles. Many new vehicle purchasing managers are focused on vehicle acquisition price and not necessarily the best life cycle cost for the application. A few hundred dollars in capital cost can lead to thousands of missed maintenance cost opportunities. Be sure to include the appropriate people in the vehicle purchasing process.