McLaren the Formula 1 team may be having the most woeful start to season in its history, but it has not stopped McLaren the road car constructor forging ahead. It has recovered from the MP4-12C being launched before it was ready and enjoyed a tidal wave of praise for the faster, better looking and in all ways superior 650S that replaced it rather hurriedly this time last year. Since then its P1 hypercar has sold out and second hand examples are now commanding massive premiums, with the just announced 500-off 675LT tipped to do likewise in short order.

And then there is the P1 GTR. It is incredibly easy to be sniffy about a car like this, that at £1.98 million costs over £1.1 million more than the hardly cheap P1 upon which it is based, especially as it can neither be raced nor used on the road. Cars from Ferrari’s FXX programme have been attracting similar scorn for years. But even if all you do is accept that by selling over 40 units (McLaren originally thought it might do a little over 30) it does no harm whatever to either the McLaren bank balance or its image around the world, then surely it is to be welcomed.

What it proves is that when it comes to the most exotic, expensive cars in the world, McLaren is now considered in the same bracket as Ferrari, something that cannot be said even of Porsche, which has to date declined the opportunity to build a similarly racy version of its 918 hypercar. Given McLaren wasn’t even a car manufacturer five years ago, that’s quite impressive.

Technically it is fascinating too, not just for its thousand horsepower, but for a shape designed for downforce alone and a slick-shod chassis that removes the single greatest impedance to any true supercar’s performance: the need to run on all weather tyres hard enough to last for months rather than minutes. So I wasn’t about to turn down the opportunity to go to Qatar to drive it.

The flat, fast and relatively featureless Losail International Circuit is not a particular easy circuit to learn, nor is a road-going McLaren P1 a particularly easy car in which to learn it. Even after several laps getting used to its performance, it’s hard to believe there’s another closely related car waiting for me that’s much quicker still. How much quicker? They have not yet timed it but according to chief tester Chris Goodwin, between 5-10sec quicker which as anyone who had ever driven a car around a relatively short track will know, it’s a night, day and most of next week difference.

So you climb into the GTR and sit in a carbon safety cell, strong enough to render a conventional roll cage entirely redundant. Unlike road McLarens’ steering wheels which are left uncluttered by buttons, the GTR’s is said to be based on that of Lewis Hamilton’s 2008 championship-winning car and as such is plastered with them. But it starts the same way as any other McLaren – you just press the button – and so long as you can mentally tune out the apocalyptic sound blasting out of the ultra-light unsilenced Inconel exhausts, it’s no more difficult to ease out onto a track.

But there all comparisons must cease, because even relative to a street P1 (a car quick enough to have qualified eighth among the Group C cars for the last Nürburgring 1000km race held on the Nordschleife in 1983), the GTR is playing a different game.

Yes, even at this level you can easily tell there’s almost another 100bhp under your foot, not least because the GTR is a little lighter too, but the night and day difference is the Pirelli slick that unlocks and releases the true potential of the car, and in every area. There’s enough thrust to make a grown man (me) whimper, but only because the tyre can now deal with it all.

Total downforce has only increased by about 10 per cent, but added to the transformation in mechanical grip, cornering speeds will be entirely alien to anyone not already intimately acquainted with heavily bewinged, slick-shod machines. You really do need a proper seat fitting, not in order to make you feel like an F1 driver, but because if you do not, a force over 2.5 times that managed by the gravitational pull of the planet will slam you into the side of your seat and the bruises will take some time to fade.

Yet it’s probably under braking from very high speeds where the grip of the tyre and the downforce combine most effectively to make the P1 GTR feel at its most other worldly. I am 6ft 4in and robustly constructed, but at something approaching 190mph at the end of straight, there was no amount of pressure I could exert on the pedal to make me think it even approached the trigger point of the ABS. It felt closer to crashing than slowing in any conventional sense that might be recognisable to users of normal road cars.

I think it’s that I’ll remember longest from my time in the P1 GTR, with its sublime user-friendliness on the limit close behind. You might think such a car could be almost uncontainable if it broke away, but it’s actually very easy to drive. Indeed and after only a brief acquaintance, you could actually exploit the instant oversteer function provided by all that power to neutralise a front end inclined to push on what I suspect were tyres some distance past their best.

There’ll be many people who see this story and dismiss it, not caring about cars they see as irrelevant and it’s a position I understand completely. To me, however, simply gaining an insight into what our most technologically-led car company can achieve when freed from the legislative and geographical shackles of the public road makes this not just the fastest road-derived car I have ever driven, but one of the most fascinating too.