Reading Your Sidewall

ASE Certified

Phone

(606) 528-8473

Email

sales@johnnywheels.com

•

There is a lot to learn from the sidewall of your tire. Although at first glance you may think you stumbled across tire hieroglyphics, you've actually found molded into the tires side its own user manual. Caution: Never mix tires with different speed ratings on your vehicle.

		Tire Size Example P205/55R16 91W

P identifies your tire as a Passenger Tire. The P stands for P Metric. Tires with higher ply rating will generally start with LT rather than a P than it identifies the tire as a light truck tire. The LT will always have a Load Range indicated. It is important to note this for vehicles that call for LT tires. Never substitute a P Metric for an LT tire, even if all the other dimensions are the same.

205 identifies the tire section width, which is the measurement of the tire from sidewall to sidewall in millimeters. This measurement varies depending on the rim to which it is fitted.

(There are 25.4 millimeters per 1 inch.)

55 is the two-figure aspect ratio. This percentage compares the tires section height with the tires section width. For example, this aspect ratio of 55 means that the tires section height is 55% of the tires section width.

R indicates the construction used within the tires casing. R stands for radial construction. Radial tires have ply cords that extend to the beads and are laid at 90 degrees to the centerline of the tread, the carcass being stabilized by a circumferential belt. B means belted bias and D stands for diagonal bias construction. This means the ply cords extend to the beads and are laid at alternate angles less than 90 degrees to the centerline of the tread.

16 The last dimension listed in the size is the diameter of the wheel rim which is most often measured in inches. This is the exact size that this tire will fit. There are some older rims called TRX which are metric measurements like 390. You CAN NOT mix TRX rims with regular tires or visa versa.

91 The load index and speed rating, or service description are the numbers that follow the tire size. The load index tells you how much weight the tire can support when properly inflated. Load indices range from 74 - 150 for passenger tires with each numeric value corresponding to a certain carrying capacity. The carrying capacity for each value can be found on a load index chart. On each U.S. passenger car tire, the load limit is listed in pounds. European tires have the load limit listed in kilograms and sometimes pounds.

Here is a quick rating of common load indexes:

60	551	74	827	88	1234	102	1874	116	2750
61	567	75	853	89	1278	103	1929	117	2833
62	584	76	882	90	1323	104	1984	118	2911
63	600	77	908	91	1356	105	2039	119	2999
64	617	78	937	92	1389	106	2095	120	3080
65	639	79	964	93	1433	107	2149	121	3197
66	662	80	990	94	1477	108	2205	122	3308
67	677	81	1018	95	1521	109	2271	123	3410
68	695	82	1047	96	1565	110	2337	124	3528
69	717	83	1074	97	1609	111	2403	125	3638
70	739	84	1102	98	1653	112	2469
71	761	85	1135	99	1708	113	2535
72	783	86	1168	100	1764	114	2601
73	805	87	1201	101	1819	115	2679

W Speed ratings are represented by letters ranging from A to Z. Each letter coincides to the maximum speed a tire can sustain under its recommended load capacity. For instance, S is equivalent to a max speed of 112 mph. Even though a tire can perform at this speed, we do not advocate exceeding legal speed limits.

CAUTION

NEVER MIX TIRES WITH DIFFERENT SPEED RATINGS ON YOUR VEHICLE.

Speed Symbol	Speed (km/h)	Speed (mph)
A1	5	3
A2	10	6
A3	15	9
A4	20	12
A5	25	16
A6	30	19
A7	35	22
A8	40	25
B	50	31
C	60	37
D	65	40
E	70	43
F	80	50
G	90	56
J	100	62

Speed Symbol	Speed (km/h)	Speed (mph)
K	110	68
L	120	75
M	130	81
N	140	87
P	150	94
Q	160	100
R	170	106
S	180	112
T	190	118
U	200	124
H	210	130
V	240	149
W	270	168
Y	300	186
(Y)	Above 300	Above 186

DOT Serial Number

The "DOT" symbol certifies the tire manufacturer's compliance with the U.S. Department of Transportation tire safety standards. Below is a description of the serial number. Starting with the year 2000, four numbers are used for the Date of Manufacturer, first two numbers identify the week and the last two numbers identify the year of manufacturer.

Prior to year 2000 three numbers are used for the Date of manufacture, first two numbers identify the week and the last number identifies the year of manufacture. To identify tires manufactured in the 90's a decade symbol (a triangle on its side) is located at the end of the DOT serial number.

Sidewall Descriptions

Below is a quick legend to notations describing the appearance of the tire’s sidewall.

Wall Marking	Meaning	Wall Marking	Meaning
BCS	Black Circumferential Serration	RBL	Raised Black Letters
BL	Black Letters	RWL	Raised White Letters
BSL	Black Serrated Letters	RRBL	Recessed Raised Black Letters
BSB	Broken Serrated Band	SBL	Serrated Raised Letters
ENWL	Extra Narrow White Letters	SRBL	Serrated Raised Black Letters
ROBL	Raised Outlined Black Letters	SOWL	Slanted Outlined White Letter
OBL	Outlined Black Letters	SVSB	Slanted Vertical Serrated Band
OGL	Outlined Gold Letters	VSB	Vertical Serrated Band
ORBL	Outlined Raised Black Letters	WL	White Letters
ORWL	Outlined Raised White Letters	WS	White Stripe
OWL	Outline White Letters	WW	White Wall