The Caterham Seven is one of the lightest, purest sports cars on the planet. Stripped of most everything that doesn’t help you go fast or have fun, a mid-spec 270 will get you to 60 mph (96 km/h) in 5.0 seconds and weighs just 1,190 lbs (540 kg), or around a third of a Porsche 911 Carrera 4S.

But the latest Seven 170 makes every other model in the range look about as trim as a three-row SUV. Weighing in at an incredible 970 lbs (440 kg), it’s the lightest Seven the company has ever built. The W16 engine alone in Bugatti’s Chiron hypercar weighs 110 lbs (50 kg) more than this entire Caterham.

Related: Caterham Will Launch An Electric Version Of The Iconic Seven

You might expect that this feat has been achieved with fancy materials that send the price skyrocketing, but the £22,990 ($31,900) Seven 170 is in fact the most affordable car in the current Caterham range. For that money, though, which is 50 per cent more than the old 160 cost back in 2013, you’ll have to build it yourself; turnkey cars cost upwards of £25k.

It’s also the narrowest, the 57.9-inch (1470 mm) width making it 4.1 inches (105 mm) narrower than the next slimmest Seven, and 10 mm skinnier than the older 160 it replaces. That reduction in width is, of course, partially responsible for the 110 lbs (50 kg) weight reduction, while also allowing it to continue to meet Japanese Kei mini-car rules.

Power comes from the same 660 cc turbocharged three-cylinder Suzuki engine, on this occasion making 83 hp and 86 lb ft of torque, that’s driving the rear wheels via a solid rear axle.

Two versions are available. The comfort-biased 170S picks up where the 160 left off and comes with a full screen and weather gear, plus black leather seats, 14-inch wheels and a Momo steering wheel. Caterham quotes a 6.9-second 0-62 mph (0-100 km/h) time and a 100 mph (160 km/h) top speed.

The yin to the S’s yang is the track-focused 170R, which dispenses with the screen but adds composite race seats, harnesses, firmer suspension and a limited-slip differential. And it’s only the 170R that achieves that record-breaking 970 lbs/440 kg curb weight. That 170 name, by the way, refers to the power to weight figure in hp per tonne, though it was decided on by marketing types, not engineers. Technically, the R comes in at 190 hp per tonne, and the 110 lbs (50 kg) heavier S, at 180 hp per tonne.

The 170 is the first Caterham conceived since the company’s takeover by Japan-based VT Holdings and is available to order now in Europe, either as a kit or fully built.

Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine
Caterham’s Lightest Seven Ever Weighs Less Than A Bugatti Chiron’s Engine