Tyre race to beat electric car ‘sound of silence’
THE race is quickening to cope with the ‘sound of silence’ in electric cars so buyers will not wonder where all the noise is coming from.
As electric car model spans increase, they are going to highlight ever smaller amounts of road/tyre rumble, as well as previously unnoticed deficiencies in a car’s build (uneven gaps) that would generate wind noise.
Andreas Puerschel, head of Hankook’s EU Development Team, told me of the challenge. Existing engines blot out a lot of road and wind sound because even the best of them are noisier than virtually-silent electric cars.
Mr Puerschel has a large team developing tyres solely for electric cars (EVs). Like their rivals, his company has been dealing with tyres’ rolling resistance for years. Now the challenge is coping with quieter EVs. Such cars are lighter too but have all their torque from the get-go – so there are conflicting demands across the board. “Customers won’t want what they consider to be noisier cars,” he told Motors.
With electric car numbers forecast to significantly increase, tyres comprise a key component in shaping the future. Hankook experts also say we need to reduce tyre width to reduce fuel consumption – but they still need current traction/ grip levels.
Latest tyres help cut 3/4pc fuel consumption a year, they reckon. But that can’t continue indefinitely, hence the need to make narrower tyres.
ONLY a few kilometres from the Russian border and way inside the Arctic Circle in the far north of Finland, a new testing complex for tyres has just been opened.
It is a long, long way to go and cold (temperatures can drop to -30C). But there is a reason for tyre-maker Hankook doing so.
For a start, it completes the circle for the variety of testing they conduct at other centres.
And it helps that snow and ice are guaranteed for so long each year – and that an existing huge independent testing facility run by Milwood is nearby.
We don’t bother much with winter tyres in Ireland. Indeed we don’t bother much with tyres at all considering the state of some.
The technology behind them now is extraordinary; I was lucky enough to catch a glimpse of it first hand.
First,I drove on snow that was fairly loose. The tyres had studs. The Hankook test expert had monitoring stuff to pick up on the tiniest variations in grip, speed and braking. It takes real trust to slam on the brakes at 50kmh and end up keeping a straight line and coming safely to a halt 30 metres later. My times (three attempts) varied by 0.2 of a second; minimal but critical at this level of development and maybe the difference between life and death in real conditions.
The same applied across packed snow with ordinary winter tyres – no studs. The level of grip, and of course the car technology (ABS, ESC etc) again kept me around the 30m mark.
On sheer ice I floored the accelerator and then braked at 50kmh. No skidding, no fish-tailing and a 30m stopping distance.
That was the Objective Testing circuit where everything is monitored and analysed to the last detail. If we could all see the level of commitment we’d think about, and treat, our tyres a lot differently. And we do take ABS and ESC for granted.
There is also a Subjective testing track where experienced drivers assess more on feel and sense than pure figures.
This is an ultra sensitive area when you consider that Hankook are developing and producing tyres for the likes of Mercedes, BMW, Audi and Porsche as well as many mainstream marques. Tiny, tiny fractions can have huge ramifications on how a car handles and feels. The tyres have to be in tune with the suspension set-up down to minute measurements. But the human sense is vital – almost like someone tasting wine.
We sped over the winding, fast, hilly, snow-packed course. You should also have seen the test driver take a Mercedes C-Class and a BMW 7-series (all traction controls switched off). Scary, but also inclined to induce a great faith in what a set of tyres can do.
It was all too short, really, like the days up here this time of year. But with the temperatures hitting -16C we went inside where, among other things we could see and feel, thanks to hand-held pieces of tyre profile, the different pliability of tyres for different roads, vehicles, climate conditions and, of course, prices.
It was informative, for example, to see how near-impossible it was to bend a runflat tyre wall compared with one for more conventional cars.
Senior Hankook management explained things in great detail. Such is the diversity of demand, we were told how they have specific engineering groups/teams for companies and vehicle types. The key challenge, as always, is sportiness versus comfort.
There is also a massive push on to reduce dependency on natural rubber – mostly from south east Asia – because resources are being stretched to the limit by demand, especially from China.
A tyre is a bit like a cake; lots of ingredients are blended. You want soft and pliant? They gave us a ball of tyre material to drop too see how it bounced – high. Another one barely rebounded.
And yes, dandelions can produce a natural latex alternative to rubber, but it has to be genetically modified to increase the precious material 30-fold for it to be economically viable. It is a really long term process.
I left Ivalo with one over-arching lesson: if cars and tyres can work like that in such extreme conditions, you’d feel reassured under normal circumstances. That’s why tyres matter and why we should pay more attention to them.