Extreme McLaren 765LT Spider makes debut

The 2021 McLaren 765LT Spider has emerged overnight – a roofless version of the hard-core coupe that's claimed to be both the fastest drop-top the British supercar-maker has ever built and also its most engaging track-focused Longtail model yet.

Mirroring the coupe, McLaren has confirmed it will limit production of the new 765LT Spider to 765 units, with each one priced from £301,500 ($A565,500) in the UK.

Weighing in at 1388kg, the 765LT Spider is 49kg heavier than a 765LT coupe but 80kg less than the equivalent 720S Spider.

It comes with extreme weight-saving measures including a carbon-fibre folding roof, however the regular Spider's glass flying buttresses remain and the rear window can still be lowered to allow occupants to hear more of the standard titanium sports exhaust.

Lowering the roof still takes just 11 seconds at speeds of up to 50km/h, and to save weight the single roof panel has a noise-reducing foam core built in. Liberating space, designers have extended the length of the actual panel, boosting headroom.

Sharing the same twin-turbocharged 4.0-litre V8 as the coupe, the McLaren drop-top pumps out an identical 563kW and 800Nm. Even with the extra weight, the 765LT Spider is capable of matching the coupe's 2.8sec 0-100km/h time and its 7.2sec sprint from 0-200km/h.

To keep it stable at the high speeds associated with driving on track, the McLaren 765LT Spider features many of the same air-bending aids as the coupe, including its front splitter and bumper, side skirts and door blade, plus its rear bumper.

The 765LT Spider also sports the same active Longtail rear wing, but it has been recalibrated to account for whether it is travelling roof up or down.

In total, McLaren claims it produces 25 per cent more downforce than a standard 720S Spider, while the seven-speed dual-clutch transmission features shorter ratios for 15 per cent quicker in-gear acceleration.

Within the cabin, the extreme weight-saving theme continues with a pair of lightweight Alcantara-wrapped seats and door nets in place of pockets. The floor carpets, air-conditioning and audio system have also been deleted.

Both the air-con and the audio system can be added back in, with the latter a no-cost option that offers Bluetooth integration and voice recognition that's operated though the standard 8.0-inch infotainment system.

Also helping save weight is a pair of lighter doors compared to the coupe that miss out on the upper carbon-fibre frame and only need a single hinge to open.

Like the 765LT coupe, McLaren Special Operations will offer a full range of personalisation options that include a Clubsport pack that incorporates yet more weight-saving measures and the carbon bucket seats from the Senna hypercar.

Optional carbon-ceramic brakes and a track telemetry system can also be added.

There's an almost endless range of exterior and interior colour combinations, plus a new LT Black Pack that adds a gloss black finish to the tonneau cover, bumper, air intakes and mirror casings.

In the UK, the 765LT Spider commands a price premium of around £30,000 ($A57,000) over the coupe, suggesting that Down Under it could be priced from a devilish $A666,000 (plus on-road costs).