I am at Turn 7 in the picturesque Anglesey Circuit here, pumping the brakes of a hulking Bentley Bentayga Speed and trying frantically to shave off excess speed.

It is clear my instructor, ex-Bentley racer Guy Smith, is trying hard not to give me a tongue lashing for not heeding his instructions, but I redeem myself by accelerating down the next straight with a loud bellow originating from the car's W12 engine.

The Speed cannot evade the laws of physics, but it comes very close.

Sharing the same platform as the Porsche Cayenne, Audi Q8 and Lamborghini Urus, the Bentayga Speed has great pedigree.

To earn the "Speed" badge, engineers at Crewe revised the software governing the car's 6-litre W12 to deliver 626hp - 26hp more than the regular Bentayga.

Peak torque remains unchanged at 900Nm, but is now spread across a wider range of engine speed.

The result is 0-to-100kmh in 3.9 seconds (0.2 seconds quicker) and a top speed of 306kmh (5kmh higher). The Speed also retains the electronic differential and dynamic driving modes that all Bentaygas share, but has firmer shocks and a louder exhaust.

It also gets the same Bentley Dynamic Ride system that helps flatten the car in corners, powered by a 48-volt electrical system.

Bespoke "Speed" badging on the headrests, passenger-side fascia and treadplates remind you of the $1.1 million (without options or a certificate of entitlement) you will pay for this Victorian house on wheels.

All those features add up to a substantial car weighing 2.5 tonnes.

With all that weight, how does the Speed fare on the tracks? Quite well, actually. Despite its heft, the car handles brilliantly.

In Sport mode, the W12 becomes more responsive to throttle inputs and the exhaust takes on a harder-edged note.

Mashing the throttle into the plush carpet, the revs flare and the Speed's exhaust goes from a hum to a sharp bark.

An unending surge from all six litres of swept displacement is creamy and unbroken, delivered in a way which goads you on corner after corner.

For a car its size, the Speed turns sharply through slower corners, but its huge engine pulls the nose wide through the faster ones. Then the car's torque vectoring system kicks in to bring the nose back in line.

Any body roll is held impressively in check. And the carbon-ceramic brakes on the test car deliver fuss-and fade-free performance.

After my run, Guy and I swopped places for him to take me out on a hot lap.

With so much opulence surrounding you, being driven in a Bentayga Speed by a racing driver is like drifting in Buckingham Palace.

Despite a mere increase in power, the Bentayga Speed feels special. That it is currently the world's fastest SUV - pipping the Lamborghini Urus by 1kmh - is incidental.

• The writer is with Torque, a motoring monthly published by SPH Magazines.