New tires make for a better match between vehicle and job need
Tires for Class 3-6 trucks have historically been general purpose offerings, which made sense because they often served in personal use applications. Even those used in commerce - pickups and vans used by plumbers, electricians, and farmers, for example - usually had low annual mileage and maintenance schedules similar to passenger cars.
While vehicles at the higher end of the range (Class 5-6) tended to be scaled down versions of larger trucks, they were often built with low-cost, standardized components - school buses, for example. They were also the last to abandon tube-type bias ply tires in favor of tubeless radials.
Notable exceptions include Class 4-6 trucks imported from Japan and Europe, which were often fitted with 17.5-in. tires, and vehicles used in one-way rental service, where security concerns and a high incidence of customer-inflicted damage made fleets reluctant to upgrade tires.
More recently, however, market changes have driven the emergence of two distinctly different families of tires for vehicles in the Class 3-6 range. We'll call the traditional general purpose tires "personal service" and the newer upgraded tires "commercial service."
Several factors have contributed to this market distinction. Growth in the package-delivery industry (serving both residential and business customers) has accelerated dramatically and is expected to continue with the increase in Internet shopping. Fleets in this market place a particularly strong emphasis on productivity and cost-effectiveness, including control of operating costs.
In addition, other commercial truck operators have been re-evaluating their vehicle requirements with an eye to downsizing trucks by more exact matching of equipment to job requirements. Utility service companies, state and municipal road departments, and others are continuing this trend. Vehicle manufacturers have responded with new midsize offerings with fuel-efficient d iesels and beefed up chassis components. For a number of years fleets have been pushing for development of smaller-truck tires with the cost-saving designs perfected for Class 7-8 vehicles.
We can think of these new commercial tires as scaled-down versions of larger truck tires, and of the personal use tires as scaled-up versions of modern passenger car tires. Each group has advantages when matched to service conditions and vehicle type. When the match is not a good one, however, safety concerns and customer dissatisfaction may result.
Most new commercial tires mirror their radial-ply 22.5- and 24.5-in. siblings. Nearly all have steel plies and steel-belt packages, and reinforced sidewalls to resist abrasion. They're designed for multiple retreads and compatibility with repair procedures and materials used on larger truck tires. Sidewall designs are purely functional and tread designs tend to be high-mass.
Manufacturers offer all-position highway rib- and drive-axle-specific tread types, with a common casing size to simplify retread usage. Selected sizes are also offered in deeper, on/off-road designs usually fitted to all-wheel-drive trucks in commercial service applications.
Although some tire sizes are offered in personal and commercial service types, load ratings may be different. Therefore, it's important to check the vehicle manufacturer's tire size and load range requirements. Also, mixing tire types across an axle is usually not recommended. In certain cases, the higher-load commercial tires also require special higher-rated wheel designs, so retrofitting may not be a viable option. Any questions or concerns about tire selection or mixing on a vehicle should be directed to truck and tire OEMs.
While up-front costs can be higher, these newly evolved products often provide lower life-cycle operating costs in demanding applications. You've got lots to choose from; make it your business to know what's out there.