Clarkson on: tyres

The other day, Richard Hammond was in the Top Gear production office, which used to be a Portakabin until the Fifties, when environmental health officers declared it unfit for human habitation.

Anyway, there he was, among the disease and pestilence, and dead rats, and Douglas Bader’s old ration books, telling James and me that, not that long ago, he went on a hiking holiday with some friends and that, late one night, in the pitch black, on a remote moor, they’d made werewolf noises to scare away a couple who’d parked up to do sex.

James and I sat with a look of pure incredulity on our faces. A hiking holiday? At night? On a remote moor? What possible pleasure could be garnered from that, we wondered? And so begins the thrust of today’s sermon: cloning. Richard Hammond is a human being, which means that, like all human beings, he is, genetically speaking, 98 per cent identical to a cauliflower. And according to recent research, a staggering 99.4 per cent identical to a chimpanzee.

Amazing isn’t it? If you took out his DNA and tried to copy it, you’d only need to get the maths wrong by 0.6 per cent, and the end result could legally be used as a research tool for smoking and the dangers of wearing make-up. Get it wrong by 0.2 per cent and he’d be Neanderthal. Get it wrong by a measurement so small it doesn’t register and he’d be James May.

No, really. Richard’s DNA and James’s DNA are so close that only the largest computer could possibly spot the difference. A butterfly only need flap its wings in Richard’s spinal column and he’d want to grow his hair and take four hours to do anything.

We see films these days where cloning is accepted as something easy, something that’s just around the corner. The Island. Jurassic Park. And, of course, The Boys from Brazil. But the simple fact of the matter is this: a former Nazi in South America may try to grow a perfect copy of Hitler, but he only need get his maths wrong by the tiniest fraction and the Fourth Reich will end up being started by Jade Goody. Or a pig. Which is the same thing.

We read, too, about genetically modified wheat. It all sounds brilliant: altering the structure of the plant to make it impervious to blight and capable of growing with very little water. But computers do make mistakes, so who’s to say that, one day, some poor farmer won’t sow his field with wheat seed and come back five months later to find he has two-and-a-half million Hitlers swaying in the breeze? It might happen.

Then you have Dolly the sheep. They took a cell from the breast of a sheep, fused it with another and popped it into a womb to incubate. But I bet the scientists were holding their breath when the labour began because for all they knew, the mother could well have squeezed out Esther Rantzen.

Let’s simplify things a bit here. There’s talk at the moment that someone with lung disease could conceivably grow a new set of bellows from one of his own stem cells. Brilliant. But who’s to say that the stem cell you choose won’t grow into a lung? It might become an ear, or a penis... and that, of course, brings me neatly on to the Seat Leon diesel.

I accidentally drove one the other day, which annoyed me greatly. This is because I went for years without driving any sort of Seat and then it became a sort of inner challenge: to see if I could go a lifetime in this job without ever driving one. But it was cold, and I needed to get off our test track and into the Portakabin, and it was just sitting there, with its key in the ignition, so I jumped in without thinking.

I’ve always assumed that the Leon would be like a Golf, but with hairy armpits. This is because we know that beneath the flamboyant Barcelona exterior, it’s genetically identical to Wolfsburg’s finest. You can even order it with the Golf’s DSG gearbox. So I’ve never seen the point. If you want a Golf for less, then you just go and buy a Skoda.

I accidentally drove one the other day, which annoyed me greatly. This is because I went for years without driving any sort of Seat and then it became a sort of inner challenge: to see if I could go a lifetime in this job without ever driving one. But it was cold, and I needed to get off our test track and into the Portakabin, and it was just sitting there, with its key in the ignition, so I jumped in without thinking.

I’ve always assumed that the Leon would be like a Golf, but with hairy armpits. This is because we know that beneath the flamboyant Barcelona exterior, it’s genetically identical to Wolfsburg’s finest. You can even order it with the Golf’s DSG gearbox. So I’ve never seen the point. If you want a Golf for less, then you just go and buy a Skoda.

The thing is, though, that on only the briefest of drives, I can tell you that the Leon doesn’t feel like a Golf at all. And this has cheered me enormously.

Like all petrolheads, I’ve been fretting recently about the way car makers are all getting into bed with one another and sharing all their corporate secrets. You’ve got a Peugeot 207 with an engine from the Mini. You’ve got a Nissan 350Z with the engine from a Renault Vel Satis. You’ve got a Jag with an S-Class gearbox. You’ve got a Mercedes SLK with the word Mercedes crossed out and Crossfire written on, in crayon. And so on and so on.

In the old days, cars were all different, but we’re heading to a point where there will be only five or six car makers in the world. And I’ve been worried that everything they offer will come from the same genetic pool. They’ll all have brakes from the same place, aircon from the same place, satnav systems from the same place and wiper motors from the same place.

At the moment, a Mitsubishi Evo VIX feels nothing like a Fiat Punto. But what if the two firms join and start to source their components from the same company? What if Ford and GM bite the bullet and become one giant corporation? What if Toyota swallows Honda? Then what? All cars will be the same.

The worst case I’ve come across is the Bentley Continental, which by rights should feel nothing like the Volkswagen Phaeton on which it’s loosely based. One is a turbocharged two-door coupe weighed down with chromed this and leather that. The other is a four-door saloon that no one likes, apart from me, and the Pope. But despite this, every time I close my eyes in a GT, I can feel the DNA of the VW shining through. It concerns me.

Well, if the Leon is anything to go by, we needn’t worry because even cars with similar genetics can be made to feel... separate. By giving it a different body, the Spaniard doesn’t look anything like its German twin. And you only need tweak the suspension genetics by a quarter of one per cent and, as we know from examples in the natural world, it’s enough to turn wheat into Hitler.

I’ve been staggered recently by the difference you can make to a car by changing its tyres. Pirellis give excellent grip for two, or perhaps three laps of our track, but then they are effectively spent. Bridgestones give off a lot of smoke, but they handle consistently for lap after lap. So two identical cars with just four of the 15,000 components changed and you end up with two products as completely different as James and Richard. Both human. Both men. Both like cars. Both hate football. But the same? Not even slightly. One’s heterosexual for a kick off...

And the other goes on camping holidays with his mates and, instead of filming people having sex and then putting them on YouTube, makes howling noises instead. Weirdwolf more like.