What is it?
The Ariel Atom 3 Mugen is a variant of Ariel's Atom to slot between the base 245bhp version and the 300bhp Supercharged. Tuned to 270bhp by Mugen (Honda's family-founded but independent tuning arm), it's also more track-focused than the other pair, which are ostensibly road-biased cars.
The Mugen wears the springs and dampers of the V8, has four-pot brake calipers, ventilated discs and a limited-slip differential while there's the V8's digital dash on the inside (I say 'inside', but you know what I mean). Production is limited to 10 units and they all get the natty red/white colour scheme (a flip of the colours available).
What's it like?
Mugen has performed the initial tuning on the 2.0-litre Type R engine, with Ariel's final tweaking making its delivery suit the lightweight flyer. It revs to about 8600rpm, where it also makes peak power, and that's good enough, so it's claimed, for a 0-60mph sprint in around 3.0sec. I can believe it.
Getting this sort of power from a naturally aspirated lump hasn't come without some compromises though. While a 'normal' Atom is easygoing at any speeds, there are two at which the Mugen is happy: pottering around at low revs, where the engine's docile enough but you'll not like the ride. Or there's the zone beyond a 4000-5000 flat spot where, you'll be unsurprised to learn, it's much better. Much, much, better.
The Atom Mugen gets more rewarding the harder you push it. Its engine is peachy, with a ridiculously loud induction snarl right by your left ear making it preferable, for me, to the supercharged car. Keep it in its powerband and it's absolutely epic.
Ditto the suspension, whose firmness gives it brilliant body control, and allows terrific feedback and adjustability. It doesn't take to poorly surfaced roads too well, but on smoother asphalt it's superb, and it'd devour tracks for fun. You've also got to try a bit harder than in a Supercharged to get the best from it, you need to keep it on the boil. Do that and it's an intoxicating experience.
Should I buy one?
Maybe. At £49,740 the Atom Mugen it isn't cheap, but this is arguably the most rewarding Atom to drive hard. If you'd mainly use one as a road car, it's probably not for you. But as a track-biased tool it's superb: the more you put in, the more you get back. It might just be our favourite Atom of the moment.
Ariel Atom 3 Mugen
Price: £49,740; Top speed: 150mph; 0-60mph: 3.0sec; Economy: na; Co2: na; Kerbweight: 550kg; Engine: 4cyls, 1998cc, petrol; Power: 270bhp at 8600rpm; Torque: 188lb ft at 6000rpm; Gearbox: 6-spd manual