What will the commercial over-the-roadtruck tire (or its worthy replacement) look like in 10 to 20 years? Although wecan’t evaluate currently unknown innovations, we can look at developments inother tire types: race, passenger car, aircraft, military and other nichemarket applications.
We now have run-flat passenger car tires that have successfully obsoleted sparetires in some vehicles. Initial complaints of harsh ride, stranded motoristsand higher tire cost are being addressed gradually with technologyimprovements. Certain space-conscious new vehicle designs no longer accommodatethe weight and space of a spare. However, to-date, run-flats still account forless than 2 % of all new passenger tires and carry a significant weight penaltyof 10% to 15%. This isn’t much on a 35-lb. car tire; the absence of a fifthtire/wheel, jack, lug wrench, etc. more than offsets the extra 2 to 4 lbs. ofeach run-flat.
However, this concept would add 15 to 20 lbs. per tire to every 295/75R22.5,and a total of approximately 315 lbs. to every 18-wheeler. Also, since trucktires operate at much higher inflation pressures and loads, the run-flatconcept of more rigid, load-supporting sidewalls will likely not extrapolate tomodern truck radials. Consider also that run-flat car tire applications havebeen driven by vehicle manufacturers in search of fuel efficiency and packagingconstraints, while future truck tire designs will be driven, to a much greaterextent, by end users.
While run-flats are designed to allow motorists to travel to the nearest tireservice facility, they are not designed to continue on to a load drop ordistant truck terminal. So, what we can expect to see instead is fairly rapidgrowth of self-sealing truck tires. Truck tires manufactured with an integralsealant are designed to stop inflation loss when punctured, generally sealinginjuries up to ¼-in. until long-term plug/patch repairs can be made to preservecasing integrity. There is currently a weight penalty for this new category oftruck tires, but we can expect this difference, and fuel economy, ofself-sealing tires to become minimal compared to conventional tires.
Another trend recognizes that truck tire rotations to different wheel/axlelocations are becoming minimal, except when tires are dismounted forretreading. This opens an opportunity for directional and asymmetric treaddesigns. This is especially significant as single wide tires replace duals ondrive and trail axles, since directional drive or trail tires would no longerhave to be reverse mounted for inner and outer dual fitment.
Remember the primary reason duals were introduced was that the tire industryhad neither the reinforcement materials nor the technology to raise single tireload ratings as fast as truck axle loading was increasing in the period from1917 through the mid-1920s. Single wide tires should become the norm, beginningwith weight-conscious bulk haulers, then extending throughout the entirehigh-speed linehaul segment. They will provide improved fuel efficiency versuscomparable dual tire fitments, reduce mounted tire inventories, and requireeight fewer TPMS sensors on a typical 18-wheeler.
Directional tread patterns to date have shown limited success in retardingirregular or fast wear in some applications, but future use might also deliverimprovements in rolling resistance, wet traction (especially under light loadconditions, and control of splash/spray patterns during heavy rain conditions.
Chines (sidewall contours resembling deflectors) currently used on someaircraft tires to direct tire spray away from jet air intakes during heavy raintakeoffs and landings may also be incorporated to reduce a major complaint manymotorists have when passing trucks at highway speeds.
Some futurists have predicted that rubber tires may be replaced by complexmetal, plastic or exotic materials woven in geometric shapes designed to roll,support loads, deliver wet and dry traction and transfer cornering forces withthe advantages of being puncture proof, having replaceable wear surfaces andrequiring no inflation pressure beyond ambient. A brief survey of industryexperts suggests that such devices might find limited use in exotic militaryapplications, but that development for highway use in the next 20 years seemsunlikely.
The information presented here is just an overview, but considering theprogress made by tire manufacturers in the past several decades, you never knowwhat the future holds.