The string of numbers and letters on a tyre sidewall are easy to decode with a little explanation. Known as sidewall markings, the information tells tyre technicians the size, type and performance of a tyre so it can be matched to a suitable vehicle. The example below is taken from a tyre that would be fitted to a typical small car. Most sidewall markings will look something like this:
185/60 R 14 86 H
Here is a handy breakdown of the information:
| Sidewall Markings | What it means |
| 185 | Width of the tyre tread in millimetres |
| 60 | The ‘aspect ratio’ is the height of the sidewall expressed as a percentage of the tyre’s width; so the sidewall height of this tyre is 60% of the tyre’s width. |
| R | Radial construction |
| 14 | Diameter of the tyre bead: this tyre will fit a 14-inch wheel rim |
| 86 | Load rating: for this example it is 530 kg* |
| H | Speed rating: for this example it is 130mph* |
*Load rating and speed rating tables are readily available online
More info
To clear up some of the terminology above, here are a few more things to explain about car tyres.
Radial tyres: The majority of tyres manufactured today are made using radial construction. Its improved strength, flexibility and rolling resistance means the tyre can last for many more miles, has a softer ride quality and achieves better mileage.
Load rating: This is the load that each tyre can carry; however, if you plan to carry heavy loads with your vehicle, check with the manufacturer as to the vehicle’s recommended maximum load capacity.
Speed rating: The speed rating is decided after thorough testing. Engineers run the tyre and accelerate in 6.2mph increments. The tyre is run for 10 minutes at each increment until the desired maximum speed is reached. The tyre is adequately ‘warmed up’ during incremental acceleration and therefore represents typical running conditions.
Recommendations
It is easier than ever to understand the technical details of your car. There are countless articles online, covering every car question imaginable (like this one), and you can now use your registration number on many car parts supplier’s websites to match tools and parts to your exact vehicle. Tyre suppliers have started using this technology to recommend tyres for your vehicle online, before coming into a tyre centre for fitting.
It is recommended that an expert tyre technician fits your tyres. Though DIY can be tempting, the margins for error are incredibly tight and tyre fitting is more complicated than seating the bead and inflating the tyre. A professional will balance each wheel and offer to fix any tracking problems with the car, so you can avoid feeling like you’re driving on square wheels. A technician will also happily recommend a full range of tyres to suit your car and budget. To get it right first time and save money in the long run, talk to an expert.
Oaks Services are experts in car maintenance, repairs and servicing. As a family run business we pride ourselves on friendly service and competitive pricing and operate throughout the South East. Our mechanics are highly qualified and experienced so we can get any make and model of car back on the road. To enquire about our services and special offers, get in touch today!
