The Audi TT RS is not your ordinary TT. It is one that can do 0-62mph in just 3.7 seconds. That makes the 394bhp car faster than most factory-fresh Porsche 911s, never mind every single BMW M car on sale. It will even muller a Ferrari F430 and a 997-era Porsche 911 Turbo. Yes, it’s fast.

It takes over the mantle as quickest thing this side of £50,000 from the 376bhp Mercedes-AMG A45, itself able to sprint from 0-62mph in little more than four seconds. Some may still prefer it: the Merc is £10,000 less than the Audi.

So, one has ‘RS’ in its name, the other is a five-door family hatchback. What else to compare them to, then, but a Ford Focus RS? Yes, that £31,000, 345bhp turbocharged four-wheel drive machine that’s rapidly becoming a cult car just months after launch. It’s a sterner test for the Audi and Mercedes-AMG than you’d ever believe.

Particularly on cold, bumpy slippery Welsh roads in November – conditions made for powerful, sporting four-wheel drive turbocharged cars like these, you’d imagine. The Ford delivers old-school performance motoring, all physical aggression that’s heavily dependent on the driver. If you’re good enough, it’s maybe even more rewarding than the other two.

What it isn’t is faster than them. But the Mercedes-AMG and, particularly, the Audi will quickly put a gap between themselvesand the less-powerful Ford. That they have paddleshift gearboxes, compared to the Ford’s manual, also helps. Epic yet effortless pace.

The TT is the one that really harries the others. There’s simply no getting away from it – literally, in either the Focus or the A45, you won’t shift it from your rear-view mirror. Get used to seeing those LED lights looming large. You may even hear its throbbing five-cylinder engine bellowing over yours.

Indeed, the TT’s engine is a genuine great. As Porsche switches to four-cylinder 718 Caymans, its drama and smooth flexibility something to relish. It’s a fair bit more engaging than the car itself. The TT is mighty fast, yes, but it’s not very involving with it, you’ll discover. Switch from the intensity of the Focus and it feels flat.

Photo - Jed Leicester

This is an effortless sort of speed. You’ll feel more input from the stiff reaction to bumps than you will from the fast but lifeless steering. Even the A45 is more exciting. Its steering has lots of feel, the suspension is controlled but progressive, and it breeds confidence the more you drive it. On such challenging Welsh roads, it’s brilliant.

But so fast are these cars, even deserted Welsh hillside roads aren’t enough to push them to the limit. That would be dangerously foolhardy. What you need is a closed-course tarmac rally stage. And would you believe, we had one to ourselves for the morning, courtesy of Cheshire’s Oulton Park.

Straight to the rally-bred Focus RS first, then. It should be at home on a course like this, we reckon. Surprisingly, it’s not. The brilliance on the road doesn’t translate through. The Michelin tyres struggle for grip, so it understeers with ease and generally feels imprecise. Drat.

The TT has more grip, but seems to suddenly run out of it. The four-wheel drive system isn’t used for driver thrills, but simply to pull the car straight when it does get out of control. As on the road, it’s all a bit flat and unexciting.

Enter the Mercedes-AMG once again. An exceptional on-road dynamic performance translates onto the rally course as well. It’s brilliantly adjustable, indulging you with balanced and feel-good sideways drifts. It’s not as OTT here as the Focus can be, but the technical superiority of its control is satisfaction in itself. Exceptional stuff.

Photo - Jed Leicester

It’s enough to take top spot here. Mercedes-AMG revised the A45 a year ago, and those revisions are spot-on. It’s fast, communicative and works well both on road and rally course. It’s clear what the extra spend over the Focus brings.

Not that the Focus RS is disappointing. Indeed, for £31k, it arguably over-delivers, with its great on-road handling, perfect balance and fruity pace. Ultimately though, it’s not quite able to fully slay the giants in the way we thought it might.

It’s still good enough to see off the TT, mind. Yes, it’s fast, and the engine is brilliant. But you need more than that to create a knockout sub-£50k performance car. It’s simply too muted and involving to become a genuine cult hero. For that, look to the other two. You won’t be disappointed.