It’s not easy to describe just how fast this new Caterham Seven CSR260 is. I could lob you a performance statistic — 0-60mph in 3.1sec for instance — and tell you that, by this measure at least, it is the quickest accelerating production car in the world. Ever.

But, having driven it, that doesn’t quite seem enough. So I started to think about how it compares with some of the other motors I’ve driven in the past month. These are my findings.

If you drive this £34,000 British sports car and, as I did two days later, climb aboard BMW’s £80,000 M6 supercar, you’ll wonder who left the handbrake on.

Bentley’s Flying Spur has more than twice the power of the Caterham but also four times the weight. By the time the Bentley had gathered some speed the Seven would be so far out of sight the only trace would be its howling exhaust note hanging in the air.

Ferrari’s brand new F430 is one of its greatest road cars but — at least up to speeds double the legal limit — I seriously doubt it would see which way the Caterham went.

So what then of the £515,000, 630bhp Maserati MC12? Its top speed is 205mph compared with the Caterham’s mere 155mph, so if you gave it enough space it would overtake the Seven and, at more than 15 times the price, so it should. But in the real world or even on a tight and twisting racetrack, I’d be staggered if Maserati’s most macho could drive away from Surrey’s swiftest.

It’s so fast it can reduce experienced drivers to giggling loons almost as quickly as it can reduce inexperienced passengers to gibbering wrecks. There is a serious point here: ultra-fast Caterhams of the past have needed both hard work and concentration before their potential could be extracted; by contrast driving the CSR fast is about as difficult as flossing your teeth.

Where an old Caterham would kick and buck over broken surfaces, this one glides like a limo; and while you needed 6000rpm on the clock of its predecessor, the fearsome R500, just to get its attention, this one is ready to shred tarmac at half those revs.

Twice during my day with the CSR260 I had to force myself to slow down, not because I was anywhere near the limits of either myself or the car but simply to avoid startling other road users.

Indeed it’s only when you’re on a racetrack and free from the restraints of law and common decency that you can begin to discover exactly what this extraordinary little car can do.

Road cars almost always go to pieces on racetracks just as road-legal race cars usually feel horrid on the road. But not the CSR: on the track you discover it will corner hard enough to set your survival instincts shouting while the brakes lose speed faster than anything this side of driving into an oak.

Whether you’ll find the accompanying and enduring limitations of Caterham design charming or infuriating is very much up to the individual.

On the plus side the ride quality is much improved while even tall drivers will have no problem getting comfortable. Less impressive are the tiny boot and fuel tank and the undignified struggle required to climb into it when the roof is up.

Also, you might reasonably expect any £34,000 car to arrive both painted and assembled, but not the Caterham. If you want paint (and you will), it’s another £750 and if you’d like to take delivery of a car rather than a large number of boxes that’ll put another £2,500 on the bill.

Add some comfortable seats and one or two other little goodies and you’ll soon be staring down the barrel of a £40,000 bill or, put bluntly, more than Porsche asks for a Boxster S.

But there is something else about a Caterham that to my mind enhances its appeal: its lack of pretension. Nobody ever bought a Caterham because they thought it made them look good, while that is the primary motive behind many purchases of Porsches and Ferraris.

To many, Caterham is a signpost on the M25 and that’s just fine. It’s still a car for the true enthusiast, one who is prepared to put up with all manner of shortcomings for perhaps the purest driving experience any money can buy.

If there’s a worry it’s that some might conclude it’s too much of a good thing, simply too fast for the public road.

But you can still buy slower, old-style Caterhams and spend as little as £15,000 on one; or you can gently drive the CSR to a racetrack, slap on a helmet and remind yourself what it’s like to be alive. I did and it’s an experience I’ll be reliving for a while yet.

VITAL STATISTICS

Model Caterham CSR260
Engine type Four cylinders in line, 2261cc
Power/Torque 260bhp @ 7000rpm / 200 lb ft @ 6200rpm
Transmission Six-speed manual
Fuel/CO2 n/a
Performance 0-60mph: 3.1sec / Top speed 155mph
Price £34,000 (£36,500 fully built)
Verdict Expensive but, cross-country, quite possibly the fastest car in the world
Rating 4/5

THE OPPOSITION

Model Noble M12 £49,950
For Hugely capable, good looking British supercar
Against Interior quality rather scrappy for the money

Model TVR Tamora £36,500
For Massive performance for the money, surprisingly practical
Against Questionable looks, handling not among best