Why is it important to use the recommended tyres from Porsche?
“Tyres are the first, last and only contact patch between the car and the road. That’s important to highlight because while we hear all about the phenomenal statistics, aerodynamics, downforce, and R&D that goes into the making of any car, there’s never that much chat about the tyre itself. I think it’s probably because it’s a product that is inherently boring. With tyres, there seems to be a culture of discount shopping. I get that because it is a lowest purchase. But the fact is that all that incredible engineering and technology is translated through that single contact patch. So, it doesn’t matter how good your aero is, or your stability system or whatever, it still has to translate itself to the road surface through the tyres. Sometimes I’ll see a thoroughbred car on a substandard tyre and think ‘What are you doing?’.”
What difference do manufacturer-recommended tyres make?
“There are two aspects to it – safety and performance. I had friends who have swapped tyres to something that was, let’s say, more financially appealing, which we can all totally relate to. And they said that these tyres aquaplane at 20mph less than the previous tyres. Things like this are why manufacturer-recommended tyres are different, as well as lots more we don’t think about, like road noise or wear rates. I want to give my car the best opportunity to use all of its tech.
“You wouldn’t go for a run in a pair of flip-flops. It’s the same with a car – it was designed with a specific tyre type in mind. Porsche and Michelin have developed these for years so they’re literally tailor-made for this car. And yet, when they run out, you go out and buy a pair of aftermarket tyres? You’ve got to be kidding me.”
What do the numbers on car tyres mean?
“Most tyres have a set of numbers across the tyre wall – something like 225/45/20. Let’s start with the number on the left. Here 225 means the width [in millimetres]. The higher that number, the chunkier the tyre looks when you look at the car from the back. That’s showing you how much contact patch that tyre has with the road. After that long number, you might have a number like 45, which is what the tyre companies refer to as the aspect ratio, or the tyre wall depth. And the final number – so, the 20 here – is the size of the wheel that tyre will fit to [in inches!].”
What do speed ratings mean on tyres?
“You might see a letter like ‘Y’ or ‘V’ on the side of your tyres. They can all change depending on different brands, but generally show a speed rating, which is really important – because you don’t want to put a slow tyre on a fast car. All Porsche cars also have an additional letter – “N”. An N-rated tyre, which is not to be confused with speed rating, means that the tyre was specifically developed for Porsche. With a car like the 911 (type 992), it has a NA0 marking, for example.”
Why are speed ratings important?
“If you’re on the German autobahn every day and you have a 911 Turbo S, which is capable of 200mph, the centrifugal forces at that speed are so extreme. I remember being told that they have to engineer these belts inside the structure of the tyre to stop their tendency to go egg shaped at very high speeds. That’s the kind of thing that helps explain why it’s really important to use manufacturer-approved and developed tyres.”
All Porsche cars are high performance, but what about GT line models for example. Are the right tyres even more important?
“For GT products in particular, part of the launch strategy is to set the Nürburgring lap record. And whenever Porsche sets that time, it’s usually keen to announce what tyres that car was on. That’s not just because it’s nice to share that information. Part of it is because, in order to get the most out of this car, you have to use these specific tyres because that’s what it built the car around. And that goes back to the safety aspect or just general enjoyment of driving. You don’t want to be trying to set your fastest lap on a tyre that wasn’t made for that car because everything will change, like your braking points. Anything that’s going to go fast needs the right grip. Even if you go from a Michelin Pilot Sport Cup 2 – which is a very focused track tyre – to a Cup 2 R, it’s seconds of a lap difference. It’s the same brand, just a step up, and yet it’s a totally different driving feel. So just imagine going to a different tyre manufacturer on a different compound and then trying to do the same thing. It’s like learning the feel of the car all over again.”