Last week, we looked at the meaning of the common tyre markings, or the tyre code, which are the numbers highlighted in white below, and refer to the tyre width, height, diameter load index and speed index. A summary of these these terms can be found below:

However, there are still a few more factors to consider when replacing your tyres. To give credit where it’s due, the advice below has been taken from the following sources United Tyres  and Continental Tyres

Other specifications and considerations to be aware of, when buying tyres, include

• DOT code.
• UTQG code.
• The type of tyre.
• Fuel economy.

Besides that, you should consider the following things:

• Manufacturer’s placard information.
• Whether to buy a new model or the same tyre you currently have.
• What your needs are.
• Whether to buy a new or used tyre.

Buying Tyres Check List: Things to Look for in a Tyre

DOT Code

DOT stands for the US Department of Transportation and its code is usually a combination of 10-13 digits and letters.

Image source: discounttyre.com

• Plant code.
  Every manufacturer’s plant in every country has its own 2-3-symbol code. Tyre Safety Group provides a database with all plant codes available, so you could check this information. For example, here are some registered plant codes in South Africa.

• Tyre size.
  The two following symbols show tyre size. However, this code translation isn’t for customers. It concerns manufacturers and is mostly moulded for them. These codes make it easier for them to find tyres that have to be recalled.

• Manufacturer identity number.
  This 3-4-symbol code is moulded solely for manufacturers’ purposes: they identify a tyre by this code and recall it if necessary.

• Date code.
  The main thing for the driver is the tyre’s 4-digit date code. The first pair of numbers means the week of manufacture, and the second pair indicates the year. With reference to the diagram above, the tyre was made during the 10^thweek of 2016.

The date code is vital for any driver, as it says precisely how old the tyre is. A tyre lasts for a maximum of 10 years, no matter whether it’s ridden or stored in your garage/a store. Be sure when fitting new tyres that they haven’t spent several years on the shelf. Most manufacturers recommend buying tyres once your old set turns 6 years old.

Uniform Tyre Quality Grading (UTQG) code

All decent tyres will have the UTQG code which shows estimates of 3 tyre characteristics based on the tests conducted by a particular manufacturer. This is a requirement on all passenger vehicle tyres (greater than 12”) in the US. If your tyre does not display these, there is a good chance it’s a poor-quality tyre on which no tests have been performed. Stay very far away from it.

UTQG code. Image source: kaltyre.com

• Treadwear.
  This rating is a 3-digit code, where 100 is standard wear, 200 – twice as much, etc. This is an estimate that is based on the tests run by the respective manufacturers. In extreme conditions or improper maintenance, the index may become irrelevant.

• Traction.
  This quality is evaluated in letters: AA, A, B, C, from the best to the worst. Traction test assesses stopping a vehicle on wet asphalt and concrete, measuring the coefficient in g (g-force).
  

• Temperature resistance.
  This characteristic is also measured in letters: A, B, C. It shows up to what speed a tyre can safely dissipate heat, and is measured in mph. A goes for over 185 Km/h, B – 160-185 Km/h, and C – 135-160 Km/h.

Fuel Economy

Bridgestone Firestone North America reports that buying tyres of different types can show a difference of 15-20% in fuel usage.

Some things you can do to determine which tyre will provide the best fuel economy:

• Look for tyres with low rolling resistance.
• One of the best options for fuel saving on your particular vehicle is the original equipment tyre.
• Check the tyre’s ( for fuel efficiency grade – some manufacturers provide this information.

Warranty

There are two types of warranty a tyre manufacturer can provide you with: defect protection and tread warranty. The most popular manufacturers usually provide both, offering a guarantee that the tread will last for several years.

Some tyres offer a pothole protection warranty, which can be a major drawcard if you live in Lydenburg or any other pothole-ridden area, which is to say, the majority of South Africa.

Noise

When buying tyres, choose less noisy models. When you’re driving in the city on low speeds, this factor doesn’t make much difference. However, you may want your car to be as quiet as possible when you drive on a highway, especially if you have an SUV.

All tyres make some noise due to air flowing through the tread, but you can choose a quieter one. Treads of the same type can also differ in the level of noise, so it’s better to consult a shop assistant before buying tyres.

Things to Consider Before Buying Tyres

Such placards include recommendations on the tyre choice according to the size, speed and load capacity, steering, on- and off-road specifications, etc. of your particular vehicle. Buying tyres that are bigger or smaller in size or aspect ratio can change:

• The vehicle’s condition.
  Tyres keep your vehicle over the ground, so mounting a tyre that is smaller in size will put more pressure on the rubber and increase the risk of crashing the car. Both bigger and smaller tyres may need new wheels to operate well.

• The speedometer reading.
  The reading of your car’s speedometer usually depends on a full rotation cycle of the tyre. When you change the size of your tyre, you change the length of one circle. And considering that such speedometers are manufactured for a particular rotation length, increasing or decreasing it will provide you with wrong readings.

• The automatic transmission shifts change time.
  Buying tyres of a different size will give your wheels different rotation and speed, so smaller tyres will have to rotate more to achieve the speed you need. And considering that your transmission shifts according to the speed, the shifting time may change. Aside from that, there may be an impact on your fuel consumption and uphill/downhill shifts.

It’s possible to change tyre size while avoiding these problems, but you should still consult your manufacturer agent. Also, you will need to keep the load of your car within the established parameters and adjust your transmission and speedometer.

If you don’t have your vehicle manufacturer’s manual, the same information can be found on the car. You can find it at the door edge, glove compartment door, trunk lid, or door port.

Image source: autoguide.com

Current Vs. New Tyre Model

Same Model

If you are satisfied with your current tyres, the choice shouldn’t be a problem. If you’re still using your original equipment tyres, note that they are made to perfectly match your vehicle and show all its benefits. If you notice your tyres have bad grip and slip on wet surfaces, recall whether you had such problems when you bought them. If yes, you may need to try something new; if no, your tyres are just old and/or worn out.

New Model

If you aren’t fully satisfied with the current tyres, determine the issue and search for tyres that meet your needs.

There is a trend on low-profile tyres and larger wheels, but many people complain about the harshness of their ride. In such a case, picking touring or grand-touring tyres instead of high- and ultra-high performance ones will make driving softer.

Make sure you do your research by reading about different brands of tyres, their benefits, drawbacks, and pricing. Also, read reviews on official and independent services to be prepared for what you will see in a store.  

Your Needs

When buying tyres, take a few moments to do a needs-analysis:

• Driving style.
  Determine what you need from your tyre.
  • If you need comfort and good response, choose touring tyres. They will provide you with a soft ride and good grip on dry and wet surfaces.
  • If you need performance for your sports car, choose high-performance tyres. They will provide you with good traction on dry and wet surfaces at higher speeds.

• Road.
  Do you drive more on highways or off-road?
  • If you drive a lot off the road and own a SUV or a pickup truck, consider off-road (all-terrain) or light-truck tyres. They will provide you with sufficient grip on uneven surfaces.
  • If you own a SUV or a pickup but drive on the road, think of SUV tyres. They will provide you with a comfortable on-road application of your car.
  • If you own a regular passenger or sports vehicle, think about touring or high-performance tyres.

• Regular load.
  If you drive a lot with large loads on your vehicle, consider getting tyres with a higher load index. If you own a SUV or a pickup truck and/or have a loaded trailer, consider buying tyres of LT (light-truck) or ST (special trailer) type. LT tyres will withstand extended loads and carry them in off-road conditions. ST tyres are designed especially for trailers: their sidewalls are thicker so they can carry more vertical load.

• The number of tyres you need.
  If you just need one or a pair, don’t buy the whole set, as the other tyres may age and deteriorate by the time you will need them.

New or Used

New

Why buy new tyres:

• They will provide you with 100% tread.
• There will be no patches and repairs.
• There will be no external and internal damages that may lead to an accident.
• New tyres have warranty and you are notified if the tyre is recalled.

Used

Why buy used tyres:

• By buying used tyres you get up to 90% of tread for 50% price.
• Used tyres can be in quite good condition, as some of them are taken off new cars after a couple thousand kilometres.
• You can help the environment by buying tyres that were used, as otherwise they may end up in landfills.

Choose Tyres Carefully

Your tyre choice determines the quality of your ride, as well as the speed and load of your vehicle. It also indicates whether you have wasted your money on nothing or the tyre will serve you for years. If your tyre choice is wrong, it can also jeopardize yourself and your car. The wrong size can become troublesome for your vehicle functions, and tyre age can cause tyre failure. So, make sure you have a serious attitude towards choosing the best tyres for your vehicle when you go to a tyre shop.