Caterham X330: All passion, but less is spent ...

Caterham's animal force is a match for any supercar. Sean O'Grady sees the X330 concept

The problem with any "new" Caterham car is that it looks almost identical to every other Caterham car. The new X330 Concept, for example, can get very lost in a crowd of Caterhams, as it did from time to time last week at the rally at Donington, which was held to celebrate the 50th anniversary of the Lotus 7, the progenitor of the Caterham. That is how it should be. The basic Caterham shape – long bonnet, minimal bodywork, bug-eyed headlights – is the company's greatest asset.

When Caterham bought the rights to the car from Lotus in 1973, as Lotus was busily preparing to move upmarket with the Elite, few would have thought that its production run at its new owner would far exceed its 16 years as a Lotus. A much-overused phrase seems entirely appropriate in this case: timeless classic.

The fact that the "styling", such as it is, dates back to the Lotus 7 and Lotus 6 designed by the late, great Colin Chapman back in the 1950s, only adds to the appeal. The 300 Caterham fans who turned up at Donington and raced their machines illustrated the other part of the car's charm – its abilities as a track car; racing for the common man, you might say. Caterham racing isn't as glam as Formula 1 – an ad for "the best of British bacon" dominated the track – but it is vastly more watchable.

The static display was no less gripping. Row upon row of cherished Caterhams lined the track, with the odd, rare, Lotus 7 peppered around the place. On display were a collection of historic Lotus and Caterham Sevens owned by the Caterham founder Graham Nearn, plus historic Lotus Formula 1 cars owned by Clive Chapman's Classic Team Lotus and cars from the Historic Lotus Register, including the original Lotus 6. It must have been the biggest-ever gathering of the clan, and to my eyes was a more impressive and heart-warming affair than the recent biggest ever gathering of Ferraris for the purposes of an entry in the Guinness Book of Records.

Caterhams, originally a fairly cheap kit car using engines from scrapped Ford Consuls or Cortinas, can nowadays set you back £35,000, and few bolt the thing together in their shed these days. Caterhaming is not exactly an egalitarian hobby any more; but there's more soul in the car and more passion in the owners' hearts than you'll ever see from those privileged enough to run supercars. Plus the best Caterhams available today – the CSRs and that X330 concept car – will out-accelerate most Lamborghinis, Porsches and Ferraris. So there.

You can guess from all that that I'm a fan, although having driven a few I'm more than conscious of the Caterham's shortcomings as practical transport.

Something else occurs to me, though. I have a feeling that those clever and dedicated engineers at Caterham may be approaching the limits of what they can get out of this car in the way of performance, if only because the laws of physics are starting to impinge on their efforts. The X330, for example, has a near-fantastical power-to-weight ratio of 600bhp per ton. The addition of a supercharger to the four-cylinder 2.3-litre Ford Duratec engine increases power massively from 260 to 330bhp (hence the X330 name). "Adding lightness" in the glorious Colin Chapman tradition is achieved by using lighter gauge steel in the trellis-style chassis and the use of new lightweight wheels together with an abundant use of carbon fibre for the bodywork and, indeed, seats.

Thus at Donington I witnessed a 1957-vintage shape, and not a terribly aerodynamic one, it must be said, with an equivalent power-to-weight ratio that puts it ahead of the Bugatti Veyron (521bhp per tonne) and the McLaren F1 (559bhp). Things are getting out of hand. How many of us could honestly claim that we could tame a beast such as that? Who knows where Caterham will be in 2057. Maybe it will hold the centenary rally in orbit around the Earth.