Tyre Size Calculator NZ

FAQs

How to read tyre size in NZ? To read a tyre size, look at the series of numbers and letters on the sidewall of the tyre. For example, in the size 205/65 R16 95H:

• 205: Width of the tyre in millimeters.
• 65: Aspect ratio (height of the sidewall as a percentage of the width).
• R: Radial construction.
• 16: Diameter of the wheel in inches.
• 95: Load index.
• H: Speed rating.

How much bigger tires can I go on in NZ? You can typically go up to 1-2 sizes bigger than the original tyre size. However, it’s important to ensure that the new tyres do not rub against the wheel wells or suspension components. Additionally, the overall diameter should not differ by more than 3% from the original size.

How to calculate the tyre size? To calculate the tyre size, use the formula: Overall Diameter=(Width×Aspect Ratio×2)+Wheel Diameter\text{Overall Diameter} = (\text{Width} \times \text{Aspect Ratio} \times 2) + \text{Wheel Diameter}Overall Diameter=(Width×Aspect Ratio×2)+Wheel Diameter Convert the width to inches (divide by 25.4), and then calculate the aspect ratio as a percentage of the width.

How do I find out what tyre size I need? Check the vehicle’s owner’s manual, the placard on the driver’s door jamb, or the current tyres’ sidewalls for the recommended tyre size.

What does 205 65 R16 95H mean?

• 205: Tyre width in millimeters.
• 65: Aspect ratio (65% of the tyre’s width).
• R: Radial construction.
• 16: Wheel diameter in inches.
• 95: Load index (maximum load capacity).
• H: Speed rating (maximum speed the tyre can handle).

What does 205 65 R16 95V mean?

• 205: Tyre width in millimeters.
• 65: Aspect ratio.
• R: Radial construction.
• 16: Wheel diameter in inches.
• 95: Load index.
• V: Speed rating (higher speed than H).

What are the tyre laws in New Zealand?

• Tyres must have at least 1.5mm tread depth.
• Tyres must be free from cuts, cracks, and other damage.
• All tyres must be the same type (e.g., all radials) on a single axle.
• The overall tyre diameter should not vary by more than 5% from the manufacturer’s specification.

Can I use 225 45R17 instead of 215 45R17? Yes, but the 225 width is wider and may affect clearance, handling, and fuel efficiency. Ensure there’s enough clearance in the wheel wells.

Can I use 205 65 R16 instead of 205 55R16? No, the overall diameter will increase, which can affect the speedometer reading and vehicle handling.

Can I put 55 tires instead of 45? Yes, but changing the aspect ratio will affect the overall diameter, speedometer accuracy, and possibly the handling of the vehicle.

Can I use 215 tires instead of 225? Yes, but 215 tyres are narrower and may affect grip and handling slightly.

Can I use 275 tires instead of 265? Yes, but 275 tyres are wider, which may affect clearance and handling. Ensure there’s enough space in the wheel wells.

What does R mean on tyres? R stands for radial construction, where the internal layers run radially across the tyre.

Can I change my tyre size? Yes, but you should maintain an overall diameter within 3% of the original size to avoid issues with speedometer accuracy, handling, and clearance.

What does C mean on tyres? C stands for commercial, indicating tyres designed for vans and light trucks with higher load capacities.

What is the difference between 205 55 R16 and 205 60 R16? The 205/60 R16 tyre has a higher sidewall (60% of 205 mm) compared to the 205/55 R16 (55% of 205 mm), resulting in a larger overall diameter.

Can I fit H rated tyres instead of V? Yes, H-rated tyres have a lower maximum speed rating than V-rated tyres, but if your vehicle doesn’t exceed the H-rating speed, it’s generally acceptable.

What is the difference between 205 60 R16 and 205 65 R16? The 205/65 R16 tyre has a higher sidewall (65% of 205 mm) compared to the 205/60 R16 (60% of 205 mm), resulting in a larger overall diameter.

What does V and H mean on tyres?

• V: Speed rating up to 240 km/h (149 mph).
• H: Speed rating up to 210 km/h (130 mph).

Can I use 215 60 R16 instead of 205 55 R16? No, the overall diameter will increase, which can affect speedometer reading and vehicle handling.

What does V and R mean on tyres?

• V: Speed rating.
• R: Radial construction.

Why are snow tyres illegal in NZ? Snow tyres with metal studs are illegal on public roads because they can damage the road surface.

Is it illegal to have no spare tyre in NZ? No, it’s not illegal, but having a spare tyre is recommended for safety.

How long should tyres last in NZ? Tyres typically last 5-7 years, but this depends on usage, driving conditions, and maintenance.

Can I fit 235 tyres instead of 225? Yes, but 235 tyres are wider, which may affect clearance and handling. Ensure there’s enough space in the wheel wells.

Can I use 215 50R17 instead of 225 45R17? Yes, but the overall diameter will change slightly, which can affect speedometer accuracy and handling.

Can I fit 205 tyres instead of 215? Yes, but 205 tyres are narrower and may affect grip and handling slightly.

How much taller is a 65 tire than a 55? Approximately 20 mm taller, depending on the width of the tyre.

Can I fit 55 profile tyres instead of 50? Yes, but the overall diameter will increase slightly, which can affect speedometer accuracy and handling.

Can I use 215 60 R16 instead of 225 60 R16? Yes, but 215 tyres are narrower, which may affect grip and handling slightly.

How much taller is a 225 tire than a 215? Approximately 10 mm taller, depending on the aspect ratio.

Is 45 a low profile tyre? Yes, tyres with an aspect ratio of 45 or lower are considered low profile.

What is the difference between 225 45 and 225 55?

• 225/45: Lower sidewall height (45% of 225 mm), resulting in a smaller overall diameter.
• 225/55: Higher sidewall height (55% of 225 mm), resulting in a larger overall diameter.