2021 MAZDA MODEL MX-5 MIATA RF Owners Manual

P215/65R15 95H is an example of a tire size and load index rating. Here is an explanation
of the various components of tha t tire size and load index rating. Note that the tire size and
load index rating may be different from the example.
P
Indicates a tire that may be ins talled on cars, SUVs, minivans and light trucks as designated
by the Tire and Rim Association (T&RA).
NOTE
If your tire size does not begin with a letter this may mean it is designated by either ETRTO
(European Tire and Rim Technical Organization) or JATMA (Japan Tire Manufacturing
Association).
215
“215” is the nominal width of the tire in millimeters. This thr ee-digit number gives the
width in millimeters of the tire from sidewall edge to sidewall edge. In general, the larger
the number, the wider the tire.
65
“65” is the aspect ratio. This two-digit number indicates the t ire's ratio of height to width.
R
“R” is the tire construction symbol. R indicates “Radial ply co nstruction”.
15
“15” is the wheel rim diameter in inches.
95
“95” is the Load Index. This two-or three-digit number indicate s how much weight each tire
can support.
H
“H” is the speed rating. The speed rating denotes the maximum s peed for which the use of
the tire is rated.
Letter Rating Speed Rating
Q9 9 m ph
R1 06 m ph
S 112 mph
T 118 mph
U1 24 m ph
H1 30 m ph
Customer Information and Reporting Safety Defects
Tire Information (U.S.A.)
8-26
MX-5_8JS9-EA-20K_Edition1_old 2020-8-28 13:50:01

Letter RatingSpeed Rating
V 149 mph
W 168
* mph
Y 186
* mph
* For tires with a maximum speed capability over 149 mph, tire manufacturers sometimes use the letters ZR. For
tires with a maximum speed cap ability over 186 mph, tire manufa cturers always use the letters ZR.
MS or M/S: Mud and Snow
AT: All Terrain.
AS: All Season. The “M
S” or “M/S” indicates that the tire has some functional use in mud
and snow.
U.S. DOT Tire Identifi cation Number (TIN)
This begins with the letters “DOT” which indicates the tire mee ts all federal standards. The
next two numbers or letters are the plant code where it was man ufactured, and the last four
numbers represent the week and year the tire was manufactured. For example, the numbers
457 means the 45st week of 1997. After 2000 the numbers go to f our digits. For example,
the number 2102 means the 21th week of 2002. The other numbers are marketing codes
used at the manufacturer's discretion. This information is used to contact consumers if a tire
defect requires a recall.
Tire Ply Composition and Materials Used
The number of plies indicates the number of layers of rubber-co ated fabric in the tire. In
general, the greater the number of plies, the more weight a tir e can support. Tire
manufacturers also must indicate the tire materials, which incl ude steel, nylon, polyester,
and other.
Maximum Load Rating
This number indicates the maximum load in kilograms and pounds that can be carried by the
tire.
Maximum Permissible Inflation Pressure
This number is the greatest amoun t of air pressure that should ever be put in the tire under
normal driving conditions.
Tread Wear, Traction and Temperature Grades
Tr e a d w e a r : The tread wear grade is a comparative rating based on the wear rate of the tire
when tested under controlled con ditions on a specified government test course. For
example, a tire graded 150 would wear one and one-half (1 1/2) times as well on the
government course as a tire graded 100.
Customer Information and Reporting Safety Defects
Tire Information (U.S.A.)
8-27
MX-5_8JS9-EA-20K_Edition1_old 2020-8-28 13:50:01

Traction: The traction grades, from highe st to lowest are AA, A, B, and C. The grades
represent the tire's ability to stop on wet pavement as measure d under controlled conditions
on specified government test surfaces of asphalt and concrete. A tire marked C may have
poor traction performance.
Te m p e r a t u r e : The temperature grades are A (the highest), B and C, represent ing the tire's
resistance to the generation of heat and its ability to dissipa te heat when tested under
controlled conditions on a spec ified indoor laboratory test whe el.
Snow Tires
In some heavy snow areas, local governments may require true sn ow tires, those with very
deeply cut tread. These tires should only be used in pairs or p laced on all four wheels. Make
sure you purchase snow tires that are the same size and construction type as the other tires
on your vehicle.
SAFETY WARNING
The following safety warning a ppears on the tire's sidewall.
SERIOUS INJURY MAY RESULT FROM:
EXPLOSION OF TIRE/RIM ASSEMBLY DUE TO IMPROPER MOUNTING-MATCH
TIRE DIAMETER TO RIM D IAMETER; NEVER EXCEED 40 psi (275 kPa) TO SEAT
BEADS-ONLY SPECIALLY TRAINED PERSONS SHOULD MOUNT TIRES.
TIRE FAILURE DUE TO UNDER-INFLATION/OVERLOADING/
DAMAGE-FOLLOW OWNER'S MANUAL AND PLACARD IN
VEHICLE-FREQUENTLY CHECK INFLATION PRESSURE AND INSPECT FOR
DAMAGE.
▼ Information on Temporary Tires
Please refer to the sample below.
Customer Information and Reporting Safety Defects
Tire Information (U.S.A.)
8-28
MX-5_8JS9-EA-20K_Edition1_old
2020-8-28 13:50:01

1. Temporary tires
2. Nominal width of tire in millimeters
3. Ratio of height to width (aspect ratio)
4. Diagonal
5. Rim diameter code
6. Load index & speed symbol
T115/70D16 90M is an example of a tire size and load index rating. Here is an explanation
of the various components of that tire size and load index rating. Note that the tire size and
load index rating may be different from the example.
T
Indicates a tire that may be installed on cars, SUVs, minivans and light trucks as designated
by the Tire and Rim Association (T&RA).
11 5
“115” is the nominal width of the tire in millimeters. This three-digit number gives the
width in millimeters o f the tire from sidewall edge to sidewall edge. In general, the larger
the number, the wider the tire.
70
“70” is the aspect ratio. This t wo-digit number indicates the t ire's ratio of height to width.
D
“D” is the tire construction symbol. D indicates “diagonal ply construction”.
16
“16” is the wheel rim diameter in inches.
90
“90” is the Load Index. This two-or three-digit number indicate s how much weight each tire
can support.
M
“M” is the speed rating. The speed rating denotes the maximum s peed for which the use of
the tire is rated.
Letter Rating Speed Rating
M8 1 m ph
Customer Information and Reporting Safety Defects
Tire Information (U.S.A.)
8-29
MX-5_8JS9-EA-20K_Edition1_old 2020-8-28 13:50:01

Location of the Tire Label (Placard)
You will find the tire label containing tire inflation pressure by tire size and other important
information on the driver's side B-pillar or on the edge of the driver's door frame.

SAMPLE
▼ Recommended Tire Inflation Pressure
On the tire label you will find the recommended tire inflation
pressure in both kPa and psi
for the tires installed as orig inal equipment on the vehicle. I t is very important that the
inflation pressure of the tires on your vehicle is maintained a t the recommended pressure.
You should check the tire pressure regularly to insure that the proper inflation pressure is
maintained.
Refer to Tires on page 9-9.
NOTE
Tire pressures listed on the vehicle placar d or tire information label indicate the
recommended cold tire inflation pressure, measured when the tires are cold, after the vehicle
has been parked for at least 3 hours. As you drive, the temperature in the tire warms up,
increasing the tire pressure.
Customer Information and Reporting Safety Defects
Tire Information (U.S.A.)
8-30
MX-5_8JS9-EA-20K_Edition1_old 2020-8-28 13:50:01

WARNING
Always check the tire inflation pressures on a regular basis according to the recommended
tire inflation pressure on the tire label and in conjunction with the information in this owner's
manual:
Driving your vehicle with under-inflated tires is dangerous.
Under-inflation is the most common cause of failures in any kind of tire and may result in
severe cracking, tread separation or “blowout”, with unexpected loss of vehicle control and
increased risk of injury. Under-inflation inc reases sidewall flexing and rolling resistance,
resulting in heat buildup and internal damage to the tire. It results in unnecessary tire stress,
irregular wear, loss of control and accidents. A ti re can lose up to half of its air pressure and
not appear to be flat!
It is impossible to determine whether or not tires are properly inflated just by looking at them.
▼Checking Tire Pressure
1. When you check the air pressure
, make sure the tires are cold ―meaning they are not
hot from driving even a mile.
2. Remove the cap from the valve on one tire.
3. Firmly press a tire gauge onto the valve.
4. Add air to achieve recommended air pressure.
5. If you overfill the tire, rel ease air by pushing on the metal stem in the center of the
valve. Then recheck the pressure with your tire gauge.
6. Replace the valve cap.
7. Repeat with each tire, including the spare.
NOTE
Some spare tires require higher inflation pressure.
8. Visually inspect the tires to make sure there are no nails or other objects embedded that
could poke a hole in the tire and cause an air leak.
9. Check the sidewalls to make sure there are no gouges, cuts, b ulges, cracks or other
irregularities.
Customer Information and Reporting Safety Defects
Tire Information (U.S.A.)
8-31
MX-5_8JS9-EA-20K_Edition1_old 2020-8-28 13:50:01

▼Glossary of Terms
Tire Placard:
A label indicating the OE tire sizes, recommended inflation pr essure, and the
maximum weight the vehicle can carry.
Tire Identification Number (TIN): A number on the sidewall of each tire providing
information about the tire brand and manufacturing plant, tire size, and date of manufacture.
Inflation Pressure: A measure of the amo unt of air in a tire.
kPa: Kilopascal, the metric unit for air pressure.
psi: Pounds per square inch, the English unit for air pressure.
B-pillar: The structural member at the side of the vehicle behind the fr ont door.
Original Equipment (OE): Describes components originally equipped on the vehicle.
Vehicle Load Limit: The maximum value of the combination weight of occupants and
cargo.
Bead Area of the Tire: Area of the tire next to the rim.
Sidewall Area of the Tire: Area between the bead area and the tread.
Tread Area of the Tire: Area on the perimeter of the tire that contacts the road when it's
mounted on the vehicle.

Seating capacity means the total allowable number of vehicle occupants. Seating capacity
is described on the tire label.

Production options weight is the combination weight of installed regular production
options weighing over 2.3 kilogram s in excess of the standard items which they replace, and
not previously considered in the curb weight or accessory weigh t, including heavy duty
brakes, ride levelers, roof rack, heavy duty battery, and speci al trim.

Rim is the metal support (wheel) fo r a tire or a tire and tube assembly upon which the tire
beads are seated.
Customer Information and Reporting Safety Defects
Tire Information (U.S.A.)
8-32
MX-5_8JS9-EA-20K_Edition1_old 2020-8-28 13:50:01

Tire Maintenance
Improper or inadequate vehicle maintenance can cause tires to w ear abnormally. Here are
some important maintenance points:
▼ Tire Inflation Pressure
Inspect all tire pressu
re monthly (including the spare) when th e tires are cold. Maintain
recommended pressures for the best ride, top handling, and mini mum tire wear. Use the
pressures specified on the vehicle tire information placard or tire label for optimum service.
▼Tire Rotation
To equalize tread wear, rotate the tires every 12,000 km (7,500
miles) at the latest or sooner
if irregular wear develops. Mazda recommends to rotate every 8, 000 km (5,000 miles) to
help increase tire life and d istribute wear more evenly.
Do not include (TEMPORARY USE ONLY)
spare tire in rotation.Forward
Inspect the tires for uneven wear and damage. Abnormal wear is
usually caused by one or a
combination of the following:
Incorrect tire pressure
Improper wheel alignment
Out-of-balance wheel
Severe braking
After rotation, inflate all tire pressures to specification (pa ge 9-9) and inspect the lug nuts
for tightness.
CAUTION
Rotate unidirectional tires and radial tires that have an asymmetrical tread pattern or studs
only from front to rear, not from side to side . Tire performance will be weakened if rotated
from side to side.

Customer Information and Reporting Safety Defects
Tire Information (U.S.A.)
8-33
MX-5_8JS9-EA-20K_Edition1_old 2020-8-28 13:50:01