Custom or Alloy Wheels
While custom or alloy wheels require an increased level of care over
steel wheels, it is vitally important that each customer receives
the highest level of service. There are several key points to note
when mounting Shinco tires. Following these basic precautions yields
In 1968, a new concept was introduced worldwide. The Alpha-Numeric
sizing system is a load-based system where tires are designated by
their load-carrying capacity and aspect ratio. The first letter is
the load and size relationship, with letters ranging from A to N.
The lower the letter, the smaller the size and, of course, the lower
the load-carrying capacity of the tire.
P-Metric Sizing System
To accommodate the smaller tires used on compact cars, the P-Metric
(Passenger Metric) system was created in 1976. The maximum inflation
pressures of P-Metric tires were raised for lower rolling
resistance. The P-Metric system is widely used by domestic tire
Custom or Alloy Wheels
Because Europe primarily uses the metric system of measurement, the
metric sizing system was developed. It is essentially a conversion
of the Numeric system. Section widths are notated in millimeters
instead of inches. Originally, tires not identified with an aspect
ratio were assumed to be 82-series. When 60- and 70 series tires
appeared, the aspect ratio was added to the nomenclature, similar to
the P-Metric system.
Often referred to as the
profile or series, the aspect ratio of a tire is determined by
dividing a tire's section height by its section width when the tire
is: inflated to maximum air pressure, mounted on the approved
measuring rim, and under no load.
A tire with a lower aspect ratio responds to lateral force more
than a tire with a higher aspect
ratio. The aspect
ratio affects steering stability. Generally, the shorter the
sidewall, or the lower the aspect ratio, the less time it takes to
transmit the steering input from the wheel to the tread. The result
is quicker steering response. Aspect ratio also affects the tread
contact patch. As a rule, a low profile tire produces a wider tread
contact patch. This wider tread contact patch creates a stiffer
footprint that reduces distortion and provides improved cornering
traction. Aspect ratio also impacts ride. A low profile tire usually
has a stiffer ride than the standard aspect ratio of 75 or more.
Speed rating and Load-Carrying Capacity
Many tires come with a service description added onto the end of the
tire's size. These service descriptions contain a two-digit number
(load index) and a letter (speed rating). The load index is a
representation of the maximum load each tire is designed to support.
Because the maximum tire load-carrying capacity is branded on the
tire's sidewall, the load index is used as a quick reference.
Repair of Speed-Rated
Because the tire manufacturer cannot monitor the quality of the
repairs for speed-rated tires, once such a tire is repaired for any
reason, that area ultimately diminishes the tire's designated speed
rating. This applies to Shinco tires with ratings of "N" or higher.
Although the warranty will cover warrantable conditions unrelated to
the repair area, the tire no longer is representative of its
original manufactured condition because it has been altered. As a
result, the speed rating of the tire is void after repairs have been
performed. The tire is capable of running at normal sustained
highway speeds up to 85 MPH if repairs are made following RMA
Standards. Punctures and nail holes up to 1/4 inch diameter which
are confined to the tread area may be patched permanently only from
the inside of the tire along with filling the perforation of the
tread caused by the nail. NEVER REPAIR TIRES WORN BELOW 2/32 INCH
TREAD DEPTH. Some OE vehicle manufacturers do not allow repairs of
Repair of Run-Flat Tires
Advan Sport ZPS Run-Flat tires are not to be repaired following an
injury. The tire will be replaced on a prorated basis under the
terms of the limited warranty for AVS Sport Run-Flat tires. Never
mix Run-Flat tires with tires that do not have Run-Flat technology.
Never mix Run-Flat tires with different brands or technologies.
Use the following
chart to determine the maximum load-carrying capacity based on a
tire's load index:
Guidelines for Speed-Rated Tires
When replacing a tire designated with a speed rating, the new tire's
speed rating should be equal or higher than the tire speed rating of
the OE placard. This rule is to avoid conflicting tire speed
capabilities and the possibility of misapplication, particularly
because one tire may be constructed to perform under a higher speed
than another. If tires with different speed ratings are mounted on
the same vehicle, the lowest speed rated tire dictates the maximum
Speed ratings are certified maximum sustained speed designations
assigned to passenger car radials and high performance tires.
Because of the evolution of high-speed passenger car travel, it was
necessary to establish a way to rate a tire's high-speed capability.
In the U.S., these ratings are based on tire testing in laboratory
conditions under simulated loads. For a tire to be speed rated, it
must meet certain minimum industry standards for reaching and
sustaining that specified speed. Domestically, high performance
tires typically are speed rated. Shinco defines high performance
tires with a speed symbol of "H, Q, V, W, Y," or "Z". Speed symbols
may currently be marked on a tire in any of three ways: 205/60ZR15;
205/60ZR15 89W; or 205/60R15 89W. The International Standard
Organization (ISO) system currently serves as a worldwide standard
for tire markings. At the end of a transition period, any speed
symbol denoting a fixed maximum speed capability will be at the end
of the service description following the tire marking (illustrated
in the second and third examples above).
The Tire Industry Safety Council bulletin says:
"A reasonable person realizes that driving speeds are dictated by
many factors, particularly such things as the weather, road surface
and mechanical condition of the vehicle. These tire symbols do not
mean that motorists can drive safely at the maximum speed for which
the tire is rated or in excess of the posted speed limits."
If tires with different speed ratings are mounted on the same
vehicle, the tire with the lowest rating will dictate safe maximum
Open Ended Speed Category
Speed ratings apply only to the tire, not to the vehicle. Putting a
speed rated tire on any car does not mean the car can be operated at
the tire's rated speed.
* This refers to tires that have a maximum speed capability above
240 KM/H (149 MPH). "Z" may appear in the size designation. Tires
that have a maximum speed capability above 300 KM/H (186 MPH) must
have a "Z" appear in the size designation. Consult the tire
manufacturer for maximum speed when there is no Service Description.
Winter Tires and Speed Ratings
To maintain tire speed capacity indicated on the vehicle placard,
winter tires with the same or higher speed rating should be used. If
you decide to use winter tires with speed ratings below what is
shown on the vehicle placard, the maximum vehicle operating speed
must be reduced to the lowest tire speed rating of the tire mounted
on the vehicle. In all cases, Shinco recommends operating speeds not
in excess of legal posted speed limits and that speed be reduced
appropriately based on weather and road conditions. Winter tire
speed ratings do not indicate safe vehicle operating speeds for
winter road conditions, including snow, ice, water etc., and drivers
must modify vehicular speeds based upon adverse climate changes and
Ply Rating vs. Load Range
Ply ratings and load ranges identify load and inflation limits of a
given tire size when used in a specific type of service.
Conservative driving at the speed limit may improve MPG by 5% in the
city and 33% on the highway.
A reduction of 100 pounds of weight in your trunk, (such as tools or
sporting equipment) can lead to 1 to 2% better MPG.
Uniform Tire Quality Grade (UTQG) Labeling
Required by the government, the UTQG provides comparative
manufacturer information. Tires are subjected to a series of
government-mandated tests that measure performance in treadwear,
traction and temperature resistance. All testing is done by the tire
Treadwear is a measurement of tread durability. Tested against
an industry standard, the assigned numerical grade indicates how
well the tread lasts compared with a reference standard of 100.
A treadwear rating of 200 means the tread wears twice as well as
the standard. Actual wear depends on the conditions under which
the tire is used. Driving habits, service practices, differences
in road surface and varying climates all affect treadwear.
Traction is a measurement of a tire's ability to stop on wet
test surfaces of asphalt and concrete under controlled
conditions. Traction grades are assigned by the UTQG system and
branded on the sidewall. Traction grade is determined only for
straight-ahead, wet braking on concrete and asphalt. It doesn't
include cornering, which may also be an important customer
Traction Grade A: The tire performed well on both surfaces.
Traction Grade B: The tire performed well on at least one of the
Traction Grade C: The tire performed poorly on one or both of
The UTQG also provides a measure of resistance to heat
generation under normal operating conditions. The test is
conducted under predetermined standards for inflation and
loading. Excessive speed, underinflation and overloading can all
cause adverse heat build-up. Sustained high temperatures can
reduce tire durability. Resistance grades are branded on the
Resistance Grade A: The maximum performance level indicating the
tire withstood a half-hour run at 115 mph without failing.
Resistance Grade B: The tire passed 100 mph but not 115 mph.
Resistance Grade C: The minimum performance level indicating
that the tire failed to complete a half-hour at 100 mph.
Transportation (DOT) Certification
"DOT" is branded on the tire's sidewall indicating the tire is
certified by the Department of Transportation. Following the DOT
branding is a serial number designating the tire manufacturer,
manufacturing plant, tire size and date of manufacture. Federal
law requires that tire dealers record the DOT identification
numbers along with the tire buyer's name and address.
Additional Tire Labeling Conventions
Mud and Snow Labeling
If a tire is rated for safe performance in mud and snow, it will
be noted on the sidewall of the tire with either M/S, M+S or
M&S. A tire is certified under the definitions set forth by the
Rubber Manufacturers Association (RMA).
Tire Construction Labeling
Tread ply and sidewall ply information, including tire ply
composition and materials used, must also be identified. An
example would be: Tread: 2 Plies Rayon + 4 Plies Fiberglass
Sidewall: 2 Plies Rayon
Aramid: A synthetic fiber that is, per weight, stronger than
steel. Used in tire construction and provides excellent high
tensile strength to weight.
Aspect Ratio: An expression representing the height of the
sidewall of a tire in terms of a percentage of tire's width.
Asymmetric: When opposite sides of a tire's tread pattern are
Block Design: A tire tread pattern made of raised rubber-
Blocks: The individual, raised rubber-compound segments making
up the tread of a tire.
Carcass: That portion of a tire that is the foundation for the
tread, belts, bead and sidewall.
Casing: The structure of tire cords locked around wire beads.
Chafer: A finishing strip of calendered fabric used to protect
the tire's bead area from the rim.
Compound: The general term referring to the chemical formula for
the tread material.
Drive Wheel(s): The wheel(s) that provide the power or driving
force for a vehicle.
Filler: The material used to fill the area above the bead
between the outer and inner portion of the sidewall. Also used
in enlarged form to stiffen the lower sidewall of a tire.
Grooves: Circumferential channels between the tread ribs of a
H-Speed or H-Performance Rated: A speed category for tires with
a maximum speed capability of 130 MPH.
High Performance Tire: 1. In the tire industry, those tires with
speed ratings of S or greater and aspect ratios of 70 or less.
2. At Shinco, those tires with an aspect ratio of 70 or less and
a speed rating of H, V or Z.
Hydroplaning: Loss of traction at high speeds caused by a wedge
of water that lifts a tire off the road surface.
Light Truck Tires: Tires designed for off-the-road and
on/off-the-road use on sport/utility, small commercial and
Load Range: A method of rating a tire's load-carrying capacity
(denoted by letters such as B, C, D, etc.) with respect to its
Low-Profile: A term describing a tire with a low relative aspect
ratio or series classification.
Metric Tire Size System: A tire sizing system using the section
width (mm), aspect ratio, speed category, tire construction and
the rim diameter (inches). Example: 185/70SR13.
P-metric System: A tire sizing system using the section width
(mm), aspect ratio, type of tire construction and rim diameter
(inches). Example: P225/70R15.
Passenger Car Tire: Automobile tires featuring aspect ratios of
70 or greater, using a taller profile for increased ride
Ply: A layer of rubber-coated fabric or wire making up the tire
Radial Tire: A tire built with casing plies that cross the crown
at an angle of 90 degrees.
Ribs: Parts of a tire tread pattern created by grooves that run
circumferentially around the tire.
S-speed or S-performance rated: A speed category for tires with
a maximum speed capability of 112 MPH.
Series: A numerical representation of a tire's aspect ratio; for
example, 50 series.
Shoulder Blocks: Raised rubber-compound segments on the part of
the tire tread nearest the sidewall.
Sipes: Slits in the tire tread. Small cuts in the surface of the
tread to improve traction.
Steel Belt: A belt material used in radial tires. Its high
stiffness provides good handling and low treadwear.
Steer Wheel(s): The wheel(s) that direct the course of a
Stud Holes: Small cavities along a tire's tread designed to hold
tire studs for increased traction on snow-covered surfaces.
Tire Profile: A term representing the portion of a tire measured
as its aspect ratio or series.
Touring Performance Tire: A tire providing the ride comfort of a
passenger car tire, yet possessing high performance tire
Trailer Wheel(s): The wheel(s) of a trailer unit that neither
provide power nor direct the course of a vehicle.
Tread Blocks: Raised rubber-compound segments on the outside
visible part of a tire.
UTQG: Uniform Tire Quality Grade. A government-mandated tire
rating system based on a tire's performance in treadwear
durability, traction and temperature resistance. UTQG ratings
are branded on a tire's sidewall.
V-Speed or V-Performance Rated: A speed category for tires with
a maximum speed capability of 149 MPH.
Varied-Pitch Ratio: Variations in angles and sizes of a tire's
tread elements that reduce ride noise levels.
Z-Speed or Z-Performance Rated: A speed category for tires with
a maximum speed capability of 149+ MPH.