Wrap your head around this: the new Mercedes-AMG A45 S makes 421hp from a 2.0 4cyl turbo engine. And this isn’t some highly-strung tuner special. It’s factory-built car that comes with a long warranty and does more than 30mpg. It’s a truly astonishing engineering achievement.
Besides that headline power figure, the A45 S twists out 369lb/ft of torque. But this engine is a revver, not a lugger as peak torque is only available between 5,000rpm and 5,250rpm.
Turbo-lag shouldn’t be an issue, though, as the blower has been moved to the back of the engine bay. That means air from the turbo has less far to travel to the inlet valves and gives a fruitier exhaust note, apparently.
A new eight-speed dual-clutch gearbox sends the power to all four wheels. The effect of all that is a 0-62mph time of 3.9secs and a top speed of 168mph.
There is, of course, a standard non-S A45. That produces 387hp, 354lb/ft, takes 4.0secs to hit 62mph and is limited to 155mph. But no-one’s going to buy that.
The bodyshell has been extensively strengthened to make sure it doesn’t buckle under the pressure. The suspension has been beefed up and adaptive damping comes as standard. And there are six driving modes to choose from, running the gamut from Slippery to RACE.
Then there’s Drift mode. The simple solution would simply be to disengage the front drive shafts, but the A45 uses a complex multi-clutch rear differential that shuffles the power between the rear wheels to keep the slide going. The last Ford Focus RS used a similar set-up.
As you’d expect, the bodywork has sprouted many spoilers, splitters, diffusers, vents and stretched front wheelarches that cover a wider track and bigger tyres. We think it actually looks pretty subtle compared to the previous, steroidal A45.
Inside, we find sports seats and a generous stock of gadgets. Pretty much all the infotainment and driver assist systems Mercedes offers are either standard or optional.
If the the A45 isn’t svelte enough for your tastes, the new CLA45 arrives simultaneously. As with the previous, A45 and CLA45 are mechanically identical. The only differences you’ll notice are a 0-62mph time 0.1secs slower and a heftier price tag.
Speaking of which, Mercedes hasn’t announced how much money needs to be forked over to buy an A45 or CLA45. But don’t expect to get much change from £50,000.
By Graham King