What does 205 mean on a tyre?

In a tyre marked 205/55 R16, the number
205 represents the tyre’s nominal section
width in millimetres.

In simple terms, this tyre is approximately 205mm wide from
sidewall to sidewall under specified measuring conditions.

Does a bigger number mean a wider tyre?

Yes. For example, a 225 tyre has a greater nominal section
width than a 205 tyre.

However, that does not mean a wider tyre should automatically
be fitted to your vehicle.

What does 55 mean on a tyre?

In 205/55 R16, the number 55 is the tyre’s
aspect ratio.

It means the sidewall height is approximately 55% of the
tyre’s nominal section width.

Does 55 mean the sidewall is 55mm high?

No. This is a common misunderstanding.

The number is a percentage of the tyre width rather than a
direct measurement in millimetres.

What is a low-profile tyre?

Low-profile tyres have a relatively smaller sidewall compared
with their width.

They are commonly fitted to larger alloy wheels and
performance-orientated vehicles.

Can I change the tyre profile?

You should not change profile in isolation without considering
tyre width, wheel diameter, overall rolling circumference and
the specifications approved for the vehicle.

What does the R stand for?

The R refers to radial construction.
Radial tyres are the standard construction used for the
overwhelming majority of modern passenger cars.

What does 16 mean?

The number 16 identifies the wheel rim
diameter, measured in inches, that the tyre is designed
to fit.

A 205/55 R16 tyre is therefore designed for a 16-inch wheel.

What does 91 mean on a tyre?

The number 91 in our example is the tyre’s
load index.

The load index is a numerical code corresponding to the
maximum load the tyre can carry under specified conditions.

Is load index important when buying tyres?

Yes. Replacement tyres must have a suitable load-carrying
capacity for the vehicle.

Choosing a tyre solely because its physical dimensions appear
correct is not enough.

What does V mean on a tyre?

In our example, V is the tyre’s speed
rating.

Speed ratings are represented by letters and correspond to
maximum speeds under specified test conditions.

Does speed rating matter if I never drive fast?

Yes. The rating forms part of the tyre’s specification and
should not be treated simply as an indication of how fast
you personally intend to drive.

Where is my tyre size written?

The tyre size is moulded into the sidewall of each tyre.
Look for a sequence similar to:

205/55 R16 91V

Can I find my tyre size in the vehicle handbook?

Yes. The manufacturer’s documentation normally provides
approved tyre and wheel specifications for the vehicle.

Can my car have more than one approved tyre size?

Yes. Some vehicles are available with several wheel sizes or
different tyre specifications depending on model, trim and
equipment.

Can the front and rear tyres be different sizes?

Some vehicles use a staggered setup where the front and rear
tyres are different sizes.

This is why you should not assume all four tyres are identical
without checking.

What does XL mean on a tyre?

XL generally means Extra Load. These tyres
are designed to accommodate higher loads at specified
pressures than equivalent standard-load tyres.

What does M+S mean?

M+S stands for Mud and Snow. It is a marking associated with
certain tyre tread and design characteristics.

It should not automatically be treated as equivalent to the
Three-Peak Mountain Snowflake winter-performance marking.

What is the Three-Peak Mountain Snowflake symbol?

The Three-Peak Mountain Snowflake (3PMSF) symbol identifies
tyres that have met defined performance requirements for use
in severe snow conditions.

How can I tell how old a tyre is?

Tyres carry a date code as part of their sidewall markings.
The final four digits identify the week and year of
manufacture.

For example, 2525 would indicate manufacture
during week 25 of 2025.

Are all 205/55 R16 tyres basically the same?

No. Two tyres can have the same dimensions but differ
considerably in tread design, compound, load rating, speed
rating, wet-weather performance, efficiency, noise and price.

Should I buy budget, mid-range or premium tyres?

The most appropriate choice depends on your vehicle, annual
mileage, driving conditions, performance requirements and
budget.

Bangor Tyre Company can explain the available options rather
than simply recommending the most expensive tyre.

Can I mix different tyre brands?

Tyre compatibility involves more than the manufacturer’s
name. Size, construction, load and speed specifications,
tread characteristics and the vehicle manufacturer’s
requirements all need consideration.

How do I know which tyre is best for my car?

Start with the correct specification for the vehicle. From
there, you can compare suitable tyres according to your
mileage, type of driving, seasonal requirements and budget.

Where can I buy tyres in Bangor?

Bangor Tyre Company supplies and fits tyres for motorists in
Bangor, County Down and the surrounding North Down area.

We can help identify the correct tyre specification and
discuss suitable options for your vehicle and budget.

Can Bangor Tyre Company find my tyre size?

Yes. If you are unsure which tyres your vehicle requires,
our team can help establish the appropriate size and
specification.

Can I choose between different tyre brands?

Depending on your tyre size and availability, there may be
several suitable options across budget, mid-range and premium
tyre ranges.

We can explain the differences and help you make an informed
choice.

Do you fit tyres as well as supply them?

Yes. Bangor Tyre Company provides professional tyre fitting
alongside a range of vehicle maintenance and tyre-related
services in Bangor.