The Caterham Superlight series may as well be called Featherlight or Superfast, because that's the formula that makes the car so wonderful. That and a huge amount of power in a package bristling with simplicity.

Three version of Caterham's trackday slayer are offered: R300, R400 and most excitingly, R500. Each has a 2.0-litre Ford Duratec unit, and each boast a power-to-weight ratio more impressive than the last.

Road tester
The Superlight's beauty is its simplicity. And its massive performance

The R300 develops 175bhp at 7000rpm and 139lb ft at 6000rpm, making a 0-60 of 4.5secs possible. The R400 packs in 210bhp and 150lb ft, both peaking slightly higher in the rev range, the result here is a claim 0-62 of 3.8secs.

But the model that impresses Autocar the most is the R500. The Duratec here produces 263bhp and 177lb ft. That’s sufficiently more in both respects to better the old car’s power and torque-to-weight ratios, and that despite being 46kg heavier. It also gets the option of a six-speed sequential gearbox, launch control and a neater dashboard.

So what we’re looking at here is a car with no windscreen, no doors and a power-to-weight ratio of 520bhp per tonne. Even with this less than slender driver installed, that’s 451bhp per tonne. The old R500 produced its power as a consequence of pretty extreme tuning, resulting in a narrow powerband that needed at least 5000rpm before delivering its best. This new version makes no such demands.

At 60mph in sixth gear, roughly 3000rpm, hitting full throttle I half expect a cacophony of protest from an off-cam engine, but instead the R500 pulls cleanly, progressively and, er, rapidly. In a way, this low-end response has me worried; if it’s this quick in sixth, what will it do in second?

The answer, Caterham reckons, is 0-60mph in 2.88sec. Subjectively at least it feels monumentally, brutally and scarily fast.

From a standstill, the launch control holds the revs at 5000rpm, the engine gently misfiring, and then manages the power through first gear, enough to get up to 60mph. Once into second, though, you’re on your own, and that’s when it really starts to hit hard.

Don’t be confused by launch control; this is not traction control. In second and third gears the R500 will spin up, and if you’re foolhardy with the throttle mid-corner in fourth, you’ll be needing corrective lock. It can crack 0-100mph in under seven seconds, or faster than a Ferrari 599.

The new engine’s more progressive delivery is a real plus point, because you can use the power more confidently. There remains a noticeable point around 6000rpm where the accumulation of revs accelerates and doesn’t stop until 8500rpm, but the throttle measures out exactly the desired poke.The R500 has other merits. Firstly, that this is the best-handling Caterham I have driven, sweetly balanced and never edgy.

Secondly, the gearbox. It is an option, and an expensive one at that, but you’ll want it. It is so pure, so accurate, so visceral. You need to use the clutch to pull away, and it is advisable to use it on downshifts, but upshifts are clutchless. You simply pull the lever back (it moves just a few millimetres), and then just before clattering the rev limiter you lift the throttle by the merest fraction and the next gear engages.

This experience, the jolt through the seat and the rifle-crack noise alone are worth the financial outlay. The standard six-speed is more liveable, but who needs liveable in an car designed to put supercars to the sword on a trackday?

The R500 is a lot of money for a Caterham without a roof. It's even faster, more flexible, more reliable and better value than the old model. The R500 is not just back; it’s better in every respect.

But what of the 'lesser' models? Well, with power-to-weight ratios that few other cars can match, they're no slouches either. The R300 and R400 both feel strong well into three-figure speeds, and its 140mph top speed is impressive, particularly as it’s achieved through brute force rather than slick aerodynamics.

You'll not be disappointed regardless of which model you choose. The R500 might be best described as a weapons grade piece of kit, but the hugely potent and uncompromised R300 and R400 offer 95 per cent of the thrills for around £10,000 less.