What will the commercial over-the-road truck tire (or its worthy
replacement) look like in 10 to 20 years? Although we can't evaluate
currently unknown innovations, we can look at developments in other tire
types: race, passenger car, aircraft, military and other niche market
applications.
We now have run-flat passenger car tires that have successfully
obsoleted spare tires in some vehicles. Initial complaints of harsh
ride, stranded motorists and higher tire cost are being addressed
gradually with technology improvements. Certain space-conscious new
vehicle designs no longer accommodate the weight and space of a spare.
However, to-date, run-flats still account for less than 2% of all new
passenger tires and carry a significant weight penalty of 10% to 15%.
This isn’t much on a 35-pound. car tire; the absence of a fifth
tire/wheel, jack, lug wrench, etc. more than offsets the extra 2 to 4
pounds of each run-flat.
However, this concept would add 15 to 20 pounds per tire to every
295/75R22.5, and a total of approximately 315 pounds to every
18-wheeler. Also, since truck tires operate at much higher inflation
pressures and loads, the run-flat concept of more rigid, load supporting
sidewalls will likely not extrapolate to modern truck radials. Consider
also that run-flat car tire applications have been driven by vehicle
manufacturers in search of fuel efficiency and packaging constraints,
while future truck tire designs will be driven, to a much greater
extent, by end users.
While run-flats are designed to allow motorists to travel to the nearest
tire service facility, they are not designed to continue on to a load
drop or distant truck terminal. So, what we can expect to see instead is
fairly rapid growth of self-sealing truck tires. Truck tires
manufactured with an integral sealant are designed to stop inflation
loss when punctured, generally sealing injuries up to 1/4-inch until
long-term plug/patch repairs can be made to preserve casing integrity.
There is currently a weight penalty for this new category of truck
tires, but we can expect this difference, and fuel economy, of
self-sealing tires to become minimal compared to conventional tires.
Another trend recognizes that truck tire rotations to different
wheel/axle locations are becoming minimal, except when tires are
dismounted for retreading. This opens an opportunity for directional and
asymmetric tread designs. This is especially significant as single wide
tires replace duals on drive and trail axles, since directional drive
or trail tires would no longer have to be reverse mounted for inner and
outer dual fitment.
Remember the primary reason duals were introduced was that the tire
industry had neither the reinforcement materials nor the technology to
raise single tire load ratings as fast as truck axle loading was
increasing in the period from 1917 through the mid-1920s. Single wide
tires should become the norm, beginning with weight-conscious bulk
haulers, then extending throughout the entire high-speed linehaul
segment. They will provide improved fuel efficiency versus comparable
dual tire fitments, reduce mounted tire inventories, and require eight
fewer TPMS sensors on a typical 18-wheeler.
Directional tread patterns to date have shown limited success in
retarding irregular or fast wear in some applications, but future use
might also deliver improvements in rolling resistance, wet traction
(especially under light load conditions, and control of splash/spray
patterns during heavy rain conditions.
Chines (sidewall contours resembling deflectors) currently used on some
aircraft tires to direct tire spray away from jet air intakes during
heavy rain take-offs and landings may also be incorporated to reduce a
major complaint many motorists have when passing trucks at highway
speeds.
Some futurists have predicted that rubber tires may be replaced by
complex metal, plastic or exotic materials woven in geometric shapes
designed to roll, support loads, deliver wet and dry traction and
transfer cornering forces with the advantages of being puncture proof,
having replaceable wear surfaces and requiring no inflation pressure
beyond ambient. A brief survey of industry experts suggests that such
devices might find limited use in exotic military applications, but that
development for highway use in the next 20 years seems unlikely.
The information presented here is just an overview, but considering the
progress made by tire manufacturers in the past several decades, you
never know what the future holds.