'Hamilton yells 140, 150, 160... mph, then slams on the brakes'

Over lunch you watch the rain, small drops at first, becoming something of a monsoon. Silverstone, so dry and almost sunny earlier that morning, is now grey and drab. It's surface is awash.

Lewis Hamilton is relaxed and smiling. Earlier on he has told radio presenter Chris Moyles that he'll be driving F1 journalists round the grand prix track in a McLaren Mercedes SLR 722, and that his aim is to make somebody throw up. He ends each sodden "tour" with a doughnut, spinning the car on the throttle in its own length on the pit straight. Nobody gets out without a huge grin, even former champion Damon Hill.

"I learned a lot from that," admits the president of the British Racing Drivers' Club which owns Silverstone. He seems genuinely impressed.

It falls to me to be the last man out. You worm your way into the SLR carefully, ducking beneath the gull-wing door – it's just not cool to smack your head on it – and into the butt-hugging leather seat. Hamilton sits grinning, waiting for the seatbelt to be fastened. He is accelerating down the road almost before helpful hands have closed your door.

"Hey, it's the fast man," he smirks, knowing what they haven't told you yet, that The Independent has topped the morning's dry road runs in another SLR on the Stowe circuit.

You barely have time to consider the comment; the 722 is squirming under full power all the way to Copse. Wheelspinning in fifth gear... "How wet is it?" I ask.

"Earlier it was as bad as it was in last year's grand prix. It's a little bit better now, but there's still loads of standing water."

Being with such a laidback driver relaxes you immediately, even when Hamilton remarks, "It's still really slippery out here," as we hydroplane through Copse over 100 mph, the wipers flicking rain off the screen. A big lurch signals the arrival of Maggotts, the left-right flick that is the prelude to a series of phenomenally fast swoops that must be negotiated before the back straight. If this were the McLaren Mercedes, he'd be doing 160mph and not lifting. As it is, the Merc clings on impressively as he guides it through the fast changes of direction, as undramatically as if we were in a Mini in the dry. Every so often the back end twitches, but the traction control handles that quickly and Hamilton is happily describing the sensations he feels here in the F1 car.

"It's one of the most awesome parts of any race track in the world," he adds. "It's so quick, and the changes of direction are so fast. It's a key part of what makes Silverstone such a fabulous circuit. I love it."

He has already told everyone it would be a slow day, given the rain, but his foot is more often than not nailed to the floor as the supercharged V8 barks its way round to its 6,500rpm redline. We come out of Chapel corner at 70mph before 626bhp propels us on to a horizon that holds Stowe corner, a tightening right-hander. Hamilton is yelling now: "140, 150... 160."

He's talking miles an hour, and just as he says 160, his right foot slams down on the brakes. At 370mm in diameter the ceramic discs are larger than the original Mini's wheels. No matter how hard you use the middle pedal it is impossible to faze them.

We are well over to the right to avoid standing water and therefore on a less than ideal line, but he coaxes the car in with incredible poise given that compromise, and it's then that you give voice to the thought that has been building in your mind.

"This is child's play for you, isn't it?"

Hamilton looks over and grins as he twitches the wheel.

"Yeah!"

Down we head to Vale, a tight left-hander so slippery that even he takes it at what feels like a slow speed, but then it's another tail-twitching ride all through the right-hander at Club and up to the Abbey chicane, where the road is awash.

"This is where everybody was spinning last year," he says cheerfully. But his right foot stays planted, and suddenly we are through the left-right flick and speeding through the very fast Bridge right-hander, a corner he says he loves. It's flat in sixth in the F1 car, say 170 mph plus... We're doing close to 100 in the SLR even in the wet. The remainder of the track is more Mickey Mouse, a series of apparently bland corners where Hamilton flicks off the traction control and takes charge of correcting induced slides with an ease that is as impressive as it is fun. We head out of the last corner, the long Woodcote right-hander, at over 100. "It's pretty slippery here," he says nonchalantly. "Like driving on ice."

We finish our ride with the traditional doughnut, white pit wall and empty grandstands swirling outside our cocoon in a kaleidoscopic blur.

"It was just a matter of being sensible today," he remarks as we head for the paddock. "You could have gone wide here and there, but what for? You'd only find a couple of tenths. It was just so wet. Now if it had been dry, we could really have pushed..."

Earlier he had given another insight into the mental default of the grand prix driver. Fourteen of Fleet Street's finest had diligently flogged an SLR around the Stowe circuit, then Hamilton steps aboard. He is visibly quicker than anyone else, carrying more speed into and out of the corners.

The SLR has started to dance, sweeping round with seamless momentum and an awesome majesty as if it has truly come alive. He wastes nothing in the transition from acceleration to deceleration. Power on. Brakes on. Maximum acceleration. Maximum deceleration.

He uses those ceramic discs hard. Very hard. Demanding all they have to deliver in one massive stab. The huge Michelin tyres shriek the vehement protest that signals imminent loss of tractive effort, but he has placed the big silver car perfectly. It turns in just where he commands it to, barely steps out of line as he picks up the power the moment the transition from deceleration to turn-in has been made.

It is the perfect demonstration of the art of the race driver. He pulls into the pits with a huge grin on his face, and as he walks away to rejoin an appreciative group of onlookers an impromptu round of applause breaks out. There are flames coming from the brakes...

"Man, I love doing that," he exclaims with the insouciance of someone fully aware of how much his team are prepared to indulge their star performer. In Hamilton's realm, the SLR is just a toy, a break from the serious business. It comes back to that comment he made earlier braking from 160 mph into Stowe corner.

This day, for us mere mortals, is all about juggling a paradox: trying not to cock it up, yet trying not to be slow. Something that requires you to be relaxed and sensible even as the demon inside you prompts you to brake later, later, later. In our own ways, the 14 of us are all on our mettle. Wanting to do our best. Did I learn anything from my ride with Lewis? Of course. It was a reminder of one's own inadequacies at the wheel. And it showed how fantastic those brakes are. That served The Independent well in our subsequent wet-road runs, which netted another fastest time.

Back in the day – an expression Hamilton has been using more and more when reflecting on the history of his sport – the famed motorsport journalist Denis Jenkinson coined the term tenths, to describe to what degree of maximum ability a driver has been trying. Jenkinson figured that if you gave your maximum driving ability and skill a figure of one, you could then use tenths to describe accurately the various degrees of performance.

So how much was Lewis investing during our lap, which, to be honest, did not actually seem that fast? Three tenths?

"Two," he replies with a smile, and all of a sudden a lot more about the on-track art of the grand prix driver, especially a world champion grand prix driver, slips gently into place.

I've written about Lewis Hamilton's talent countless times, but now I really know. I've seen the absolute truth of it. First-hand. Close up.