Are Ultra-Wide,

Ultra-Low Aspect 

Ratio Tires the

Next Big Thing?

by Kevin Rohlwing

Editor and TIA Senior Vice President 

of Education and Technical Services

Almost every component on a

typical Class 8 tractor has

changed significantly over the

past decade. It’s finally reached a point

where wrenches and hand-tools are

almost useless without electronic

diagnostic equipment. Who would have

thought that modern diesel engine repair

would be impossible without a computer

and the proper software? From anti-lock

brakes to automatic power dividers,

technology has made almost every

component on today’s truck dependent

on microchips.

One area that has seemed to escape

the computer revolution from an

operational standpoint is where the

29

Commercial Tire 

s e rv i c e s e rv i c e

FEATURING

Are Ultra-Wide, Ultra-Low

Aspect Ratio Tires the

Next Big Thing? 29 

Sometimes It’s the 

Little Things 32

What’s Your Opinion? 35

Photo courtesy of Alcoa and Bridgestone/Firestone
30

commercial

tire service

rubber meets the road. Advanced

rubber compounds and tread designs

have undoubtedly improved both

performance and mileage, yet the

dependence on the correct amount of

inflation pressure has not changed.

Likewise, the tools and equipment

required to service modern tire and

wheel assemblies has basically

remained the same for the last 20 to

30 years. Computerization has

certainly played a role in the tire and

retread manufacturing processes, but

from a service perspective, the

procedures are still the same.

Unlike the automotive and light

truck tire industry, where fitments

change on an annual basis, the most

popular medium radial truck tires

continue to be the 11R22.5 and the

295/75R22.5 (275/80R22.5). These

two sizes still comprise 55 percent of

the original equipment market and 38

percent of replacements, as they have

for past 10 years. One of the main

reasons is that fleets demand

standardization, so they are extremely

reluctant to change. However, the

new economy has forced the

transportation industry to look outside

the old model and explore new ways

of cutting costs while improving

performance.

Fleets that carry high-bulk freight

like paper towels and potato chips

have turned to 17.5 and 19.5-inch

tires, so they can increase the volume

of the cargo space yet still carry the

load. Since these tire sizes can require

changes in the drive-train and braking

systems, they are limited in their

scope and acceptance. As a result,

most companies are not able to

retrofit all of their equipment to

accommodate the smaller rim

diameters, so the change must be

made on an original equipment level.

Standard wide base tires, like the

385/65R22.5 and the 445/65R22.5,

have been popular in vocational fleets

for years. Dump trucks and cement

mixers can take advantage of the

flotation properties in addition to the

extra load-carrying capacity on the

front axles. Once again, most of these

fitments come directly from the

factory, so the decision to go in that

direction must be made in advance of

a new equipment purchase.

A few years ago, the industry

introduced a radically different tire

and wheel design that allows fleets to

take advantage of the benefits of

replacing dual tires with a single tire.

These new “ultra-wide low-profile”

tires can be installed on practically

any vehicle (if it has hub-piloted

wheels) without the need to retrofit

any axle components. With the same

outside diameter as a 295/75R22.5 or

275/80R22.5, these tires do not

require any recalibration of the

speedometer or anti-lock brake system

(if present). According to the

manufacturers, fleets that utilize

ultra-low aspect ratio tires will also

experience improved fuel economy, a

smoother ride and weight savings of

around 500 pounds once dual tires are

eliminated.

From a service perspective, these

new tire and wheel configurations are

no different than any other wide-base

tire. Currently, they are restricted to

special aluminum wheels, but steel

wheels are expected to be available in

the near future (if they aren’t already).

The demount, mount, inflation and

installation procedures are also the

same as any other tubeless radial

truck tire on a wide-base hub-piloted

aluminum wheel, so the thousanddollar question is, “Will they ever

replace the 295/75R22.5 and the

275/80R22.5, the most popular

medium truck tire sizes in North

America?”

The answer is—it depends. One

of the first obstacles to overcome is

the obvious difference in appearance.

These ultra-wide, ultra-low profile tires

are a radical departure from what the

industry has grown accustomed to

over the past few decades, so businesses

that are historically resistant to

change have to alter their ways of

thinking. However, bulk haulers of

gasoline and other liquids see the

immediate advantages of the

additional 500 lbs in carrying capacity

and have led the way in retrofitting

their tractors and trailers. According

to reports from drivers, the ride

improvements are noticeable with an

increase in vehicle handling.

Which brings up the second

major issue; what happens when a tire

goes flat? One of the advantages of

dual tires is the ability to “limp” home,

a seemingly impossible scenario with

these new assemblies. Additionally,

one would think that a flat tire would

‘

... the new economy has forced the transportation industry to look outside the old model and

explore new ways of cutting costs while improving performance.

’

‘

These new ’utra-wide

low-profile‘ tires can be

installed on practically any

vehicle (if it has hub-piloted

wheels) without the need to

retrofit any axle components.

’
31

commercial

tire service

result in a drastic reduction in

handling, causing the vehicle to lose

control. Manufacturer tests have

shown that the sudden loss of air in

an ultra-wide, ultra-low profile tire

does not have a dramatic effect on

handling. In fact, one manufacturer

even devised a special internal device

that fills the air cavity to provide extra

stability in the event of a flat tire. To

summarize, losing the air in one of

these tires does reduce the ability to

“limp” home, but the effects on

handling at highway speeds in those

situations are minimal.

Another topic that always comes

up is mileage. It’s not uncommon for

modern over-the-road drive tires to

cross the magical 200,000-mile

barrier, and early returns on the

performance of ultra-wide, ultra-low

profile tires indicate similar results.

There’s also the issue

of retreading

and

whether these new tires can deliver

the same type of mileage that

traditional dual drive tire retreads

have enjoyed for years. Once again,

manufacturer tests indicate that their

retreadability and durability is

comparable to dual drive tires.

The final stumbling block is the

availability of replacement tires when

the need for emergency road service

arises. While they aren’t as common

as 295/75R22.5 or 275/80R22.5 tires,

ultra-wide, ultra-low profile tires are 

readily available at truck stops and

most dealerships that carry major

brands. On the other hand,

breakdowns in certain remote areas

that require a replacement tire may

result in a somewhat lengthy stay on

the side of the road.

On the surface, there appear to

be very few negatives about making

the switch to ultra-wide, ultra-low

profile drive and trailer tires. The

improved fuel mileage, smoother ride

and weight savings should be enough

for most fleets to give them a shot. If

transportation companies can get past

the radically different look and

educate drivers to embrace the

advantages, it’s possible that their

popularity will continue to increase as

time goes by. Will they ever replace the

295/75R22.5 or 275/80R22.5 as the

most popular tire sizes in North

America? That remains to be seen.

Just remember that fleets once

thought the 10.00-20 would always be

the workhorse and tubeless radials

were just a passing fad. And we all

know how that turned out. ■

‘

The improved fuel mileage, smoother ride and weight savings

should be enough for most fleets to give them a shot.

’

Photo courtesy of Peterbilt Motors Company and Bridgestone/Firestone