In the not-so-distant past, the realm of 600 to 700bhp was reserved for only the most exclusive and expensive hypercars.

The world has changed, though, and manufacturers are furiously downsizing engines to comply with ever-stricter emissions regulations. Does that mean we’ll see power figures dropping? Does it heck, the people love big numbers.

Still, we never really expected to see this. Essex-based tuner Mountune has now managed to extract a frankly ridiculous 684bhp from the 2.3-litre EcoBoost engine usually found in the Ford Focus RS. Crikey.

Mountune managed it by fitting its own cylinder head and a BorgWarner EFR 8374 turbocharger, whilst also running the engine on E30 fuel. Maximum torque stands at 566 lb ft.

Just to put those numbers into context, in the Focus RS this engine makes 345bhp and 347lb ft of torque on overboost. There’s also a derivative of it in the new Focus ST, which utilises 276bhp and 310lb ft.

Mountune actually reckons this is now the most powerful four-cylinder, direct-injection ever made. Unfortunately, it hasn’t been plumbed into a car just yet (the one you see above is Mountune’s 513bhp version) but at least the feat has been proved possible.

Hands up who fancies a drive in a 684bhp Focus?