Can I change my tyre size from the manufacturer’s recommendation?

Changing tyre size can affect your car’s handling, braking, and safety systems. It may also impact your roadworthiness and insurance coverage. If you are considering a different size, consult a qualified tyre professional and ensure any replacement tyres meet Australian safety standards and your vehicle’s specifications.

Why is it important to follow the recommended tyre size?

Using the correct tyre size helps maintain vehicle stability, fuel efficiency, and braking performance. It also ensures your tyres wear evenly and that safety systems, such as ABS and traction control, function correctly. Following the manufacturer’s recommendation keeps your car performing safely under typical Australian driving conditions.

What tyre size should I choose for my car?

We recommend using the tyre size specified by your vehicle manufacturer on the tyre placard, usually located inside the driver’s door, glove box, or fuel flap. Using a different tyre size may affect your car’s handling, safety, and roadworthiness, and could impact insurance coverage.

How do you determine which tyres fit my vehicle?

We match tyres based on your car’s original manufacturer-recommended size. Using our online tyre size calculator, make sure to enter your vehicle’s make, model, and year accurately. You can also search for compatible tyres using your registration number or by entering the tyre size from your current tyres. This ensures any replacement tyres meet safety and performance standards in Australia.

What do the tyre numbers mean?

The tyre sidewall, located between the wheel rim and tread, displays tyre numbers and letters that indicate the tyre’s size, construction, load capacity, and speed rating. These markings help you select tyres that fit your car safely and perform reliably. For example, a tyre marked 205/55 R16 91V means: 205 = tyre width in millimetres 55 = aspect ratio (sidewall height as a percentage of width) R16 = radial construction and wheel diameter in inches 91V = load index and speed rating Always check your vehicle’s tyre placard or owner’s manual, and use the Bridgestone tyre size calculator to confirm compatibility and ensure optimal performance.

Understanding Tyre Sizes

Calculate Tyre Size

Tyre size explained

Tyre dimensions

Width:
The section width of your tyre in millimetres, from the inner sidewall to the outer sidewall. Example: 195mm

Aspect Ratio:
The height of your tyre from the base of the tread to the rim, as a percentage of the tread width. Low profile tyres have smaller aspect ratios. Example: The height of this tyre is 65% of its width.

Tyre Construction:
The method used to construct your tyre. Example: R, for radial ply construction. This is the most common method of construction for passenger tyres.

Rim:
The diameter of the wheel rim in inches. If you are buying wheels for existing tyres, this is the size you will need. Example: 15 inches.

Load Index and Speed Symbol
The maximum load capacity under which your tyre can safely operate, and at what speed. This is subject to the tyre being in sound condition, correctly fitted, and with the recommended inflation pressure. Example: 91 V

How to find your tyre size?

Knowing how to check tyre size is straightforward. You can find your tyre size by examining the sidewall of the tyre, referencing your vehicle's owner's manual, or locating the placard inside the driver’s door jamb. Accurate tyre size ensures optimal performance, safety, and fuel efficiency.

If still uncertain about your tyre size, contact your local Bridgestone store who will be able to assist with all your tyre needs.

Read your tyre size

How to check your tyre size

Tyre size calculator, showing how to calculate your tyre size. Image of tyre width size.

Tyre size calculator, showing how to calculate your tyre size. Image of tyre rim size.

Tyre size calculator, showing how to calculate your tyre size. Image of tyre speed symbol.

Tyre size calculator, showing how to calculate your tyre size. Image of tyre load speed.

Width
Profile
Rim
Load
Speed

Indicates the section width of a tyre in millimetres.

The sidewall height measured from the base of the tread to the rim. This number represents a percentage of the tread width. Low profile tyres have smaller aspect ratio percentages.

Indicates the diameter of the wheel rim. So if you are buying wheels for existing tyres, this is the size in inches you will require.

Load indicates the maximum load capacity at which a tyre can be safely operated, subject to the tyre being in sound condition, correctly fitted and with the recommended inflation pressure. See table below for load index and the maximum load per tyre.

Load index	83	84	85	86	87	88	89	90	91	92	93	94	95	96	97	98	99
Max load/tyre (kg)	487	500	515	530	545	560	580	600	615	630	650	670	690	710	730	750	775

Speed symbol is a code which indicates the speed at which a tyre can be safely operated, subject to the tyre being in sound condition, correctly fitted and with the recommended inflation pressure. See table below for passenger tyre speed symbol ratings.

Symbol	E	F	G	J	K	L	M	N	P	Q	R	S	T	U	H	V	W	Y	Z
Rating	70	80	90	100	110	120	130	140	150	160	170	180	190	200	210	240	270	300	240+

Tyre speed rating chart

Tyre speed symbol table

Speed Symbol	Rating (Km/h)
E	70
F	80
G	90
J	100
K	110
L	120
M	130
N	140
P	150
Q	160
R	170
S	180
T	190
U	200
H	210
V	240
W	270
Y	300
Z	240+

Tyre load rating chart

Tyre load index table

Load Index	Max Load (kg)	Load Index	Max Load (kg)	Load Index	Max Load (kg)	Load Index	Max Load (kg)	Load Index	Max Load (kg)	Load Index	Max Load (kg)
60	250	85	515	110	1060	135	2180	160	4500	185	9250
61	257	86	530	111	1090	136	2240	161	4625	186	9500
62	265	87	545	112	1120	137	2300	162	4750	187	9750
63	272	88	560	113	1150	138	2360	163	4875	188	10000
64	280	89	580	114	1180	139	2430	164	5000	189	10300
65	290	90	600	115	1215	140	2500	165	5150	190	10600
66	300	91	615	116	1250	141	2575	166	5300	191	10900
67	307	92	630	117	1285	142	2650	167	5450	192	11200
68	315	93	650	118	1320	143	2725	168	5600	193	11500
69	325	94	670	119	1360	144	2800	169	5800	194	11800
70	335	95	690	120	1400	145	2900	170	6000	195	12150
71	345	96	710	121	1450	146	3000	171	6150	196	12500
72	355	97	730	122	1500	147	3075	172	6300	197	12850
73	365	98	750	123	1550	148	3150	173	6500	198	13200
74	375	99	775	124	1600	149	3250	174	6700	199	13600
75	387	100	800	125	1650	150	3350	175	6900	200	14000
76	400	101	825	126	1700	151	3450	176	7100	201	14500
77	412	102	850	127	1750	152	3550	177	7300	202	15000
79	437	104	900	129	1850	154	3750	179	7750	204	16000
80	450	105	925	130	1900	155	3875	180	8000	205	16500
81	462	106	950	131	1950	156	4000	181	8250	206	17000
82	475	107	975	132	2000	157	4125	182	8500	207	17500
83	487	108	1000	133	2060	158	4250	183	8750	208	18000
84	500	109	1030	134	2120	159	4375	184	9000	209	18500

OD:
The overall diameter of your unloaded tyre in mm.

Type Definitions:
An abbreviation providing information about the type of your tyre.

Examples:
RFT – Run Flat Technology
MOE – Mercedes Original Equipment
LRR – Low Rolling Resistance
RBT – Raised Black Letters Tubeless
OWT – Outline White Letters Tubeless
RWT – Raised White Letters Tubeless
LWT – Line White Tubeless
TT – Tube Type
TL – Tubeless
XL – Extra Load
LT – Light Truck construction
N* - Porsche specification
☆ – BMW spec

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Vehicle data is provided by Vehicle Logic

Vehicle data is provided by Vehicle Logic

Frequently asked questions

Can I change my tyre size from the manufacturer’s recommendation?

Changing tyre size can affect your car’s handling, braking, and safety systems. It may also impact your roadworthiness and insurance coverage. If you are considering a different size, consult a qualified tyre professional and ensure any replacement tyres meet Australian safety standards and your vehicle’s specifications.
Why is it important to follow the recommended tyre size?

Using the correct tyre size helps maintain vehicle stability, fuel efficiency, and braking performance. It also ensures your tyres wear evenly and that safety systems, such as ABS and traction control, function correctly. Following the manufacturer’s recommendation keeps your car performing safely under typical Australian driving conditions.
What tyre size should I choose for my car?

We recommend using the tyre size specified by your vehicle manufacturer on the tyre placard, usually located inside the driver’s door, glove box, or fuel flap. Using a different tyre size may affect your car’s handling, safety, and roadworthiness, and could impact insurance coverage.
How do you determine which tyres fit my vehicle?

We match tyres based on your car’s original manufacturer-recommended size. Using our online tyre size calculator, make sure to enter your vehicle’s make, model, and year accurately. You can also search for compatible tyres using your registration number or by entering the tyre size from your current tyres.

This ensures any replacement tyres meet safety and performance standards in Australia.
What do the tyre numbers mean?
The tyre sidewall, located between the wheel rim and tread, displays tyre numbers and letters that indicate the tyre’s size, construction, load capacity, and speed rating. These markings help you select tyres that fit your car safely and perform reliably.

For example, a tyre marked 205/55 R16 91V means:

205 = tyre width in millimetres

55 = aspect ratio (sidewall height as a percentage of width)

R16 = radial construction and wheel diameter in inches

91V = load index and speed rating

Always check your vehicle’s tyre placard or owner’s manual, and use the Bridgestone tyre size calculator to confirm compatibility and ensure optimal performance.
Width

Aspect

Rim Size

Load

Speed

The section width of your tyre in millimetres.

The sidewall height measured from the base of the tread to the rim. This number represents a percentage of the tread width. Low profile tyres have smaller aspect ratio percentages.

The diameter of the wheel rim in inches. This is the size you will need to choose if you are buying wheels for an existing tyre.

The maximum load capacity at which your tyre can be safely operated. This is subject to your tyre being in sound condition, correctly fitted and inflated at the recommended pressure.

A code indicating the speed at which your tyre can be safely operated. Again, this is subject to your tyre being in sound condition, correctly fitted and inflated at the recommended pressure.