Motoring journalist Mark Gallivan talks to Continental Tyre Group’s Tom Dennigan about understanding and choosing the right tyres for your company’s fleet.

Last year the SIMI reported a total of 88,320 new car registrations in the Republic. In 2019 that same figure was 117,109.

As successive lockdowns and business sentiment hit the dealerships in 2020 with the first quarter new registrations of 50,138 registrations the new car sales continues to decline with 48,074 new cars registered in the same first quarter of this year.

“Ideally all four tyres should be the same make and pattern for maximum benefit. However, in real life this is not always possible”

Business owners burdened with a languishing car fleet are reconsidering the necessity of upgrading to new models. Where decisions are now being made to keep the existing fleet the importance of safety is paramount. This is even more relevant to business owners with furloughed fleet lying idle for months on end. Frequently one of the most critical safety items overlooked is the condition of a car’s tyres.

I spoke with Tom Dennigan, general sales manager of Continental Tyres Group and perennial sponsor of the Irish Car of the Year Awards and asked him to demystify the common questions everyone has on the correct tyre choice and maintaining a tyre’s safety.

What is the maximum recommended number of miles Irish people should put on their tyres?

Man in blue suit with purple tie.

Tom Dennigan, general sales manager of Continental Tyres Group

“This is a question that I am often asked and unfortunately there is really no straightforward answer,” says Dennigan.

“The mileage that a driver gets from a particular set of tyres varies according to several factors; the driver’s style of driving, the road and general driving conditions, the type and performance of the vehicle, the quality and characteristics of the tyres and of course how well the driver looks after their tyres.

“You also shouldn’t forget about tyre maintenance. Checking your tyre pressures every couple of weeks and adjusting them to the recommended levels will improve the life of the tyres and help keep the vehicle safe on the road. It’s important to regularly check for damage. Another tip is to rotate the tyres from the front axle to the rear axle and vice-versa, this will also help extend the life of the tyre.”

What is the legal mileage limit that a tyre should be changed in Ireland?

“There is no legal mileage limit on tyres. Tyre mileage can vary greatly. There is however a minimum legal tread depth of 1.6 millimetres at which tyres must be changed. As this is the minimum legal limit, we recommend that you consider changing your tyres before they get to this level. New tyres will generally have a tread depth of 6 to 7 millimetres.

“As a tyre wears it will gradually lose some of its characteristics, particularly its ability to cut through water on the road which increases the risk of aquaplaning and can result in longer stopping distances on wet roads. There’s an easy way for you to check the remaining tread depth; on every tyre there is a tread wear indicator (TWI). There are several of these on every tyre in the tyre grooves. Once the tyre wears down to the tread wear indicator the tyre is at its minimum legal tread depth,’ Dennigan advises. It’s always recommended that you check your tyres every few months. Dealers often offer free vehicle health checks. Also any reputable tyre dealer will provide a free assessment of your tyres.”

For most of us the letters and numbers of the side of the tyre are meaningless. Here is your quick guide to everything from the speed index to the date and production that are visible the side of the tyre.

“There’s a vast amount of information on the sidewall of a tyre, from the manufacturer’s name and pattern, to the tyre size and maximum load/speed,” shares Dennigan. “In addition there may be specific fitment information that relates to certain vehicle makes and models. For example, many premium and performance car marques require you to fit a tyre that has been specifically developed for that vehicle. An example of a Mercedes marking is ‘MO’. Similarly some BMWs will be marked with a ‘star’, Jaguar with a ‘J’, Audi with ‘AO’.

“There is a load speed index on the sidewall of every tyre and this is always immediately after the tyre size. The tyre size might be 225/40 R18 – suggestion: 225 refers to the width of the tyres in millimetres, 40 is the percentage height of the tyre’s sidewall (the bit you see) in relation to its width (the main area that touches the tarmac) and the 18 denotes the tyre is designed to fit an 18 inch wheel rim. These figures could be followed by e.g. ‘92Y’. The ‘92Y’ is an index that is used by all tyre manufacturers to denote the maximum weight carrying capacity of the tyre at a particular speed.

“Regarding the date code on a tyre, this will be in a four figure format such as 1021. The first two numbers refer to the week and the last two numbers refer to the year. In this example, the tyre was manufactured in week 10 of 2021.

“There could be further information on the tyre’s sidewall that refers to a particular tyre type, and again this is important for motorists to be aware of when replacing their tyres. For example, the letters ‘SSR’ on the sidewall show the tyre is a runflat tyre (i.e. it provides limited capability to continue driving in the event of a puncture, e.g. to a nearby garage rather than being stranded at the roadside with a flat tyre).

“Other markings to watch for that Continental use for example include ContiSeal, which shows the tyre contains a special sealant that seals punctures in the tread area and provides motorists with extra safety and a special foam layer inside the tyre which makes it particularly quiet. ContiSilent tyres are becoming increasingly popular on electric vehicles.”

What is Dennigan’s recommendation for Irish buyers when buying a good quality tyre for winter and summer?

“First and foremost, keep to the same tyre make and pattern that came on your vehicle when it was new. Be sure also that you are keeping to the same specifications in terms of load and speed and don’t forget about the specific markings for certain vehicles. The vehicle manufacturer in conjunction with the tyre manufacturer will have carried out extensive tests to make sure that the original equipment tyres are best suited to your vehicle.

“The research and development process for creating an original equipment tyre, in conjunction with the vehicle manufacturer, can take years. Nobody knows your vehicle better than the people who made it. All tyres sold in the EU are required to have a standard EU tyre label that shows; wet grip, fuel economy and an external noise rating. From May this year, tyre labels will also include snow grip for car tyres and have a QR code on them that will allow the user to access a Product Information Sheet.”

Do Irish drivers need to by an additional set of winter tyres for Irish winters?

“We don’t have much need for winter tyres in Ireland as we tend to have milder winters than some areas of Europe. Most tyres used in Ireland are classified as summer tyres. These will not perform as well in colder conditions.

“All-season tyres are a good alternative that not only provide good performance all year round but they will perform better in the colder winter months than traditional summer tyres do. Winter tyre compounds are specially developed to maintain grip and traction in low temperatures. They are very popular in Europe and Alpine areas where there’s lots of snow and extremely cold winters.

“In some countries and regions it is a legal requirement to fit them during the winter months. They work best at temperatures below 7 degrees centigrade. They have lots of grooves and sipes to give extra grip in snow and ice. But winter tyres are not really suited to summer conditions, so once the weather warms up, they should be removed and stored over the summer months and then refitted for the following winter,” says Dennigan.

Should a typical Irish family be concerned about different tyre compounds – isn’t that for Formula 1?

Continental tyre on a Mercedes vehicle.

“Tyre manufacturers decide the tyre compounds that go into their tyres based on a multitude of criteria. For example, different compounds are used in tyres to give more grip in wet conditions or for longevity.

“Formula 1, gives an excellent example of where tyres are working to their extremes and it is common for race cars to change their tyres during a race according to the conditions on the day. For everyday motoring, Irish motorists do not need to concern themselves too much with the different compounds in their tyres but it is useful to understand some of the benefits they offer.”

Dennigan recommends buyers to always choose a premium tyre and ideally buy the same brand as originally fitted to the vehicle.

How important is the correct inflation for a tyre?

“This is absolutely critical and it’s often forgotten about by many motorists. From Continental’s own survey, we know that over 50 per cent cent of drivers drive on the wrong pressure (+/- 4psi). The recommended tyre pressure for any vehicle will be on a sticker either on the pillar inside the driver’s door, on the inside flap of the fuel filler or in the vehicle handbook.

“Maintaining the right pressure means that the right amount of rubber tread will be in contact with the road at all times. An underinflated or an overinflated tyre means that the amount of the contact patch in contact with the road surface will be reduced, therefore grip and traction will be compromised. This will also impact the tyre life and fuel consumption.”

And finally, is it okay to mix different brands as long as the four tyre sizes are the same?

“Ideally all four tyres should be the same make and pattern for maximum benefit. However, in real life this is not always possible. As a minimum, we recommend that the same tyre make and pattern are fitted across an axle. But it is not illegal to mix tyres of different makes on a vehicle as long as they are the same size.”

Written by Mark Gallivan

Published: 13 May 2021