In theory, the Mercedes-AMG CLA 45 should be exactly the same to drive as the rabid and deeply excellent Mercedes-AMG A 45. Because despite its sweeping new junior CLS lines, the CLA is actually identical to the A 45 beneath the skin.
That means originally you got the same 355bhp, 2.0-litre turbocharged four-cylinder engine as the A 45, the same crisp but direct electric power steering, the same seven-speed dual-clutch automatic gearbox, even the same spring rates for its new strut and multi-link suspension system.
Then in 2015, Mercedes-AMG decided to turn up the wick of the engine, which saw not only the A 45 suddenly produce 375bhp, but also the CLA 45 and GLA 45. All this was in direct response to Audi's audacious attempt to make the RS3 the most powerful hot hatch on the market.
The CLA 45, just like the A 45, will hit 62mph from rest in a claimed 4.2sec thanks in part to its 'race start' launch control system, and it’ll reach the same 155mph limited top speed, having hit 100mph in approximately 11.0sec en route, making a delicious noise in the process – particularly if you go for the optional AMG Performance Exhaust.
So although a dinky little four-cylinder coupé may not sound like the kind of car that would normally wear Mercedes' most prized of badges, times are a-changing, even at AMG. And in the process, the raw performance of the cars is suffering not one bit.
And when you look at what the CLA 45 AMG offers, at least on paper, it’s hard not to be impressed by the numbers it generates – except for one, which we’ll come to in a moment.
The headline figures are as follows: 375bhp, 332lb ft, 0-62mph in 4.2sec, 162g/km of CO2 and 40.9mpg on the combined cycle. That is an extraordinary series of statistics by any reckoning, and pace you can really feel on the road thanks to its grippy four-wheel-drive chassis. On wet UK roads in particular, we doubt there are many cars out there that could keep up with it.
As for the standard equipment on the CLA 45, it includes all the gubbins found on the CLA AMG 250 and adds AMG-tweaked braking and exhaust systems, suspension, and seven-speed sports transmission, along with 19in alloys, an aggressive bodykit, LED headlights and performance-styled sports seats.