What is it?
Saying a new car is better than its predecessor is about as lazy as you can get because, if it weren’t, its maker would have had to have done something very wrong indeed.
But the Ariel Atom 4 is noteworthy because it’s better to such a huge extent over the outgoing Atom 3.5 that it’s like buying a brand-new smartphone and, within 15 minutes, wondering how you ever coped with the one you’d had for years. It’s like weighing up the relative merits of a Ferrari 488 GTB versus not just a 458 Italia but perhaps even an F430. It’s a seismic shift for the car from Somerset. And feels easily as rapid as a 488 GTB too.
Perhaps this shouldn’t be surprising given that the Atom 4 represents the biggest change to the Atom since the car was first launched at the turn of the century. It has been through plenty of iterations – some more significant than others – since then, but suspension pick-up points, uprights and geometry haven’t changed so much. This time, although it looks like an Atom, it’s new from the ground up.
Quite early in the process, Ariel’s designers and engineers decided that bigger chassis tubes (as possessed by Ariel’s experimental titanium chassis, although the Atom 4’s remain steel) were the way to go, not just from a strength perspective but also a visual one. Allied to wheel diameter an inch bigger front and rear, new geometry and updated bodywork, I’d say this is the first Atom with a really purposeful visual stance.
Previously spidery like those leggy arachnids you find in the bath, there’s now a tarantula-esque muscularity to it (with deference to southern hemisphere readers, who might, I suppose, find those in the bath).
It’s a mite longer than before, although still only 3520mm, but no wider, fortunately, because at 1880mm, it’s quite wide for a lightweight car. The wheelbase is up slightly, to 2390mm, with 1600mm and 1615mm tracks front and rear. And the increased size means it’s a bit less lightweight than an Atom 3.5. At 595kg, it’s around 20kg heavier than the old car, which seems a bit of a shame, but still some way from heavy.
The hardware is all upgraded, though. The engine is now the turbocharged 2.0-litre one from the latest Honda Civic Type R, replacing the old naturally aspirated Civic unit; engines that Ariel kept stashed away after the Civic stopped using them. Ariel used to throw on a supercharger, making their respective weights and power outputs about the same, but there is now, officially, no need for any further forced induction than it already has: the new engine makes 320bhp at 6500rpm and 310lb ft from 3000rpm. That’s at 1.3 bar of boost pressure, although modes two and one on an adjustable dial take it down to 290bhp (0.6 bar) and 220bhp (0.3 bar) respectively. (Less extension of the throttle pedal achieves something similar.)
It drives the rear wheels through a limited-slip differential and six-speed manual gearbox. There are double wishbones with inboard coil-overs (our test car wearing the middle option of two upgrades), and new aluminium uprights. Three wheel options (standard, forged and carbonfibre, like these ones) are all the same size and all wear Avon ZZ tyres (ZZS as standard; grippier but less wet-happy ZZR optionally) of 195/50 R16 at the front, which is not a lot wider than before, and 255/40 R17 at the rear, which is.