The Ariel Atom 4 is not strictly the fourth iteration of this British-built lightweight special.
The first Atom arrived just in time for the millennium with 190bhp from a naturally aspirated 1.8-litre Rover engine. Launched in 2003, the Atom 2 that followed had as much as 300bhp courtesy of a new supercharged Honda engine, and that was a recipe Ariel stuck with for the Atom 3 of 2007.
But the next chapter in the Atom story dispensed with the pleasantries, at least outwardly: the winged Atom V8 of 2010 packed 500bhp from a 3.0-litre unit that started life as two Suzuki motorcycle engines. It was a mad, 25-off machine we described as being “brilliant to its core” despite the £150,000 asking price and it demonstrated that the 20 or so employees at Crewkerne could build a genuine world-beater.
Ariel returned to relative normality with the introduction of the Atom 3.5, which in 2013 reprised the 2.0-litre Honda unit in the Atom 3, only this time with up to 315bhp to go with the slimline new headlights and an even stiffer chassis. Naturally, it was subtly but noticeably better to drive than the Atom 3 and Ariel’s waiting list duly grew.
Which brings us back to this week’s road-test subject – in truth, the sixth Atom – for which only the pedals and fuel-filler cap are carried over from the Atom 3.5. By now, we’re expecting brilliance, but it’s the precise nature of that brilliance that should fascinate.