Thirty years ago this month Colin Chapman sold the rights to the Lotus Seven. The crude little sports car had helped put Lotus on the map in the late 1950s but by 1973 it had no part to play in a future populated by quasi-supercars such as the Elite, Eclat and Esprit. Had it not been for Caterham Cars, one of his dealers, the Seven would have died there and then but Caterham’s principal, Graham Nearn, believed there was life in the old roadster yet. He bought the rights, the Caterham Seven was born and, three decades later, he has long since been proved right.

I should say now that my interest in the Seven is more than purely professional. I’d owned and crashed a Caterham before I’d earned a penny writing about cars, since when I’ve owned another, built one, raced a third and done countless thousands of largely unnecessary miles in dozens of others, just because I could. Drive one and you’ll see why.

The latest offering is the £29,950 R400, so called because 200bhp in a car weighing less than half a tonne equates to a power-to-weight ratio better than 400bhp per tonne. Allow me to put that in perspective: a V12 Aston Martin Vanquish doesn’t manage 250bhp per tonne, a Ferrari 360 Modena scrapes to about 275bhp per tonne. You’d have to put the Ferrari’s engine in a car weighing rather less than the lightest Skoda Fabia even to get close.

The R400 will hit 60mph from rest in less than four seconds but because wheelspin means you can’t use anything like full power on the way there, this is a pretty poor guide to its performance. All I can say is it makes a BMW M3 look as gutsy as a Sinclair C5, and a Porsche 911 as potent as a moped.

Indeed, if the R400 has a problem it is that it is nibbling at the limits of what can safely be achieved on the public road. As traffic levels rise and tolerance of speed falls there are ever fewer places where an R400 can be driven at anything like its true capability without invoking outrage.

Of course, a properly driven R400 is one of the safest cars you can buy: its ability to stop before, dodge around or accelerate away from trouble is beyond the imagination of almost everyone who has not driven one. Sadly for Caterham, that’s not why people buy such cars.

People buy Caterhams because they are real enthusiasts; nobody would buy a car so lacking in even the smallest luxuries purely to show off to their mates. As that is the sole motivation behind the purchase of almost every convertible, the market for Caterhams is limited.

If you care the least bit about refinement or creature comforts, strike the Seven from your list: the R400 I tested came with a fabric roof, doors, a windscreen, two wipers, a heater and some paint. They’re all optional: the full windscreen (in lieu of standard wind deflector) and weather equipment cost £855 as an option.

But there are Sevens you can buy with all these seeming essentials in place, as the Caterham range is split into two model lines: the comparatively well equipped and comfortable Roadsport series for the mildly unstable and the Superlight series (R400 included) for the terminally deranged.

However, as uncompromising as Caterhams are in general, and the R400 in particular, they are not so ludicrously impractical that they should only be used on racetracks. I once took a girlfriend touring in France in a Seven and the fact that she is now my wife suggests I’ve been forgiven. Compared, for instance, with a Smart Roadster, there’s a canyon for a boot, the driving position is very cosy and the ride is not at all uncomfortable.

More than anything, though, the R400 reminds you what a car can feel like when stripped of all the stodge that comes with modern motoring. If you think your car responds instantly and accurately, drive a Seven — I mean any Seven — and you’ll think again.

The R400 provides unimaginable performance, but do not go away with the idea that this is the only way to enjoy a Seven. The basic £15,200 Classic, with half the power and at half the cost, offers just as authentic an experience. While the R400 is probably the one to choose for road and track work, my favourite is the slightly less powerful R300. It is £7,000 cheaper, has a better power-to-weight ratio than a Ferrari 360 Modena and is certainly a lot easier to exploit on the road.

But neither of these is the quickest Caterham: the R500 has been independently timed from to 60mph in 3.5sec — just 0.3sec slower than the world’s fastest production car, the McLaren F1. To date, these are the only two road cars I have ever driven whose acceleration made me scream, but the Caterham costs only £36,200.

VITAL STATISTICS
Model Caterham R400
Engine type Four cylinders, 1796cc
Power 200bhp @ 7200rpm
Torque 150 lb ft @ 5750rpm
Transmission Six-speed manual
Suspension (front) double wishbones, coil springs, anti-roll bar; (rear) De Dion axle, coil springs, anti-roll bar
Tyres 195/45 ZR 15
Acceleration 0 to 60mph: 3.9sec
Top speed 140mph
Price £29,950
Verdict Still the supercar-slayer to beat them all, 30 years on