The 415bhp Mercedes-AMG A45 S Will Do 0-62mph In 3.9 Seconds

The Mercedes-AMG range has grown by four models. Affalterbach has just rolled the new A45 and CLA45, both of which are available in even hotter S trim.

The base versions aren’t exactly sluggish: each has 382bhp to play with from a new AMG 2.0-litre inline-four turbo engine, giving a 0-62mph time of 4.1 seconds in the CLA, and four seconds dead in the A45. Go for an S, and the power figure jumps to 415bhp, chopping a tenth of the 0-62 while increasing the electronically-limited top speed from 155mph to 168mph.

It is possible to option the limiter increase in the non-S cars, but really, it’s the shoutier model you want. Not just for the increase in power: although both versions of the new ‘45 ‘M139’ engines are designed to feel N/A like, the S should feel more so, with peak torque of 369lb ft made at 5000-5250rpm compared to 354lb ft felt at 4750-5000rpm in the ‘basic’ cars. The S cars meanwhile make peak power at 6750rpm as opposed to 6500, although whatever you go for, there’ll be a zingy 7200rpm redline to enjoy.

The whole unit is flipped 180 degrees relative to both the old M133 ‘45 engine, putting the turbocharger at the rear of the block. This shortens the required ducting, reducing weight and spool-up times.

Further helping the M139 when it comes to responsiveness, the twin-scroll turbocharger itself has - like the turbos used in the AMG GT63 S 4-Door - roller bearings.

Power is sent to all-four wheels via a new eight-speed dual-clutch automatic gearbox. The four-wheel drive system has a new rear differential packing a pair of multi-disc clutches, meaning torque split can be varied between the two wheels at the back.

Exactly how the four-wheel drive system behaves depends on what drive mode you’re in, and also whether or not you’ve enabled drift mode. Yep, the A45 and CLA45 will let you engage in sideways tomfoolery, provided you’ve either opted for the S or optioned the base model with the AMG Dynamic Plus package.

Whichever A45/CLA45 you go for, three-stage adaptive dampers are optional. When it comes top stopping, base ‘45s have four-piston monoblock front calipers teamed up with 35mm discs, with single-piston floating calipers squeezing 330mm rotors at the back. The front discs on the S models at 10mm bigger, and they’re paired with six-pot calipers.

Pricing hasn’t been revealed yet, but to give you an idea of how much the A45 and CLA45 might cost, you had to stump up £41,875 and £44,695 respectively for the last two. The current A35, meanwhile, is £35,580.