205/45 R17 Tyres Explained

205/45 R17 is a common tyre size for many compact and family cars. The numbers mean the following: 205 is the tyre's overall width in millimetres. The 45 is the aspect ratio - i.e. the sidewall height is 45% of the width (about 92mm). Finally the R17 tells us that the tyre is made to fit a 17 inch wheel rim. You'll find options from premium tyre manufacturers such as Michelin, Pirelli, Bridgestone and Goodyear. And mid range options from Kumho, Hankook, Yokohama and Falken. Budget alternatives include Wanli, Mazziniand iLink. Performance models are available in this size, for example the Michelin Pilot Sport 5 and the Continental PremiumContact 7 can be found in the size 205/45 R17. To be sure this is the right size, check the tyre sidewall, the driver's door sticker or your vehicle handbook. You can also enter your registration for exact matches and correct load and speed ratings.

The tyre size that you find on the sidewall of a tyre will tell you important information such as the width, profile and diameter of your tyre. In this case, for the tyre size 205/45 R17, this means the following: 205 - the width of the tyre in millimetres. I.e. 205mm wide. 45 - the height of the sidewall as a percentage of the width. In this case 45% R17 - the diameter of the tyre's inner rim in inches. Basically what size of wheel this is designed to fit onto. In this instance it is a 17 inch wheel.

If you are looking for the recommended tyre pressure for 205/45 R17 tyres, you will find that this will depend on the manufacturer and model. Each vehicle manufacturer has their own tyre pressure recommendation for their model, that will deliver an optimal performance for your vehicle. Check the following if you are unsure what the correct tyre pressure is for your 205/45 R17 tyres Tyre label - this is often the best place to find your tyre pressure information. It is located on the door jamb on the driver’s side of the vehicle. It is a small rectangular label that provides the driver with the recommended tyre pressure and tyre sizes. Vehicle handbook - Quite often the vehicle handbook with contain a section that relates to the technical details for the tyre. This should include the required tyre size, load rating, speed rating and recommended tyre pressure.

The sidewall height of a 205/45 R17 tyre is calculated by using the profile information of the tyre size. In this instance 45. This tells us that it is 45% of the tyre's cross-section width. When looking at a tyre, the sidewall height is the distance between the tread line of the tyre and the rim line. Given that this tyre size has a cross-section width which equals 205mm, we can work out that the sidewall height is 45% of 205 – this comes to 92.25mm.