2020 Mercedes-AMG GLA punches to 421hp and 167mph!

  • High performance, high-riding compact SUV
  • Mercedes-AMG's 421hp, 2.0-litre is groundbreaking
  • The school run will be but a blur in this GLA

Since joining Mercedes-Benz's range in 2013, the GLA has been a real success story for the three-pointed star, blending family-hatchback dimensions with appealing off-road attitude. AMG's influence on the original was dramatic - but there's a new generation, and the next Mercedes-AMG GLA 45 S turns it up to 11.

2020 Mercedes-AMG GLA 45 S 4Matic+, grey, panoramic roof

Following the introduction of the second-generation GLA, Mercedes-AMG has moved fast to take this otherwise mild-mannered, premium compact SUV to frankly ridiculous levels of performance. If the old model was 'a little silly', the 2020 Mercedes-AMG GLA 45 S 4Matic+ is downright irresponsible.

Taking the school-run prestige of a soft, high-riding hatchback - now with more bootspace, class-leading MBUX infotainment and cutting-edge safety and convenience features - and extracting an astonishing 421hp from its 2.0-litre, four-cylinder turbo petrol engine flies in the face of climate change, CO2 and the call for 20mph urban speed limits around Britain. That output is the highest achieved by any current production four-cylinder turbo engine in the world, by the way...

Mercedes-AMG GLA 45 S M139 engine, 2.0-litre, 421hp, 500Nm

Mercedes-AMG GLA 45 S handling

It's not as if the AMG engineers have stopped there, either. That hand-built engine is only the start. The eight-speed automatic gearbox, also uprated for the GLA 45 S, is a dual-clutch design for fast, precise changes and it feeds into an all-wheel drive transmission that can distribute 500Nm of torque between front and rear axles, and further direct power to the rear left or right wheels selectively for optimum grip and cornering.

Mercedes-AMG GLA 45 S driving, cornering

Handling is also tuned to match the performance, with the ability to soften for daily use as well. AMG's adaptive damping and uprated brakes - the UK will only get the 45 S, with six-pot front calipers attached with F1-style engineering, and 360mm front discs - give the car the potential to react very quickly to the driver's inputs; naturally the full suite of safety tech features as well, benefitting from the sharp responses and powerful brakes.

Mercedes-AMG GLA 45 S 20-inch wheels and 6-pot brakes

Variable-ratio steering allows the drive modes of the GLA 45 S to cater for different driving environments, switching between a road-biased 'comfort' setting or more track-suited 'sporty' response to augment the six configurations (including individual) provided by AMG Dynamic Plus. The UK's 'S' specification means track-friendly features, such as launch control and 'Master' ESP modes, are included as standard, and there's a track logging function as well.

Mercedes-AMG GLA 45 S - how to spot one

All these performance-enhancing goodies aren't much use if everyone mistakes the GLA 45 S for a GLA 180. Aside from the larger brakes - and 20-inch five-twin-spoke wheels to accommodate them - the GLA 45 S gains high-power LED headlights, twin 90mm tail pipes with adjustable 'sport' or 'balanced' sound and a rear diffuser.

Flared arches, with distinctive side badging, further draw attention to the performance potential - and prestige - of the GLA 45 S. UK pricing is yet to be announced, but as the previous model hovered around the £46,000 to £53,000 mark we expect this sharper and better-equipped model to be at the upper end of that when it goes on sale in April, particularly given the increase in VED.

2020 Mercedes-AMG GLA 45 S interior with yellow accents

Inside, the A-Class-derived interior gains sporty bucket front seats with electric adjustment and half-leather (effect) trim accentuated with yellow highlights, echoed around the centre console. The AMG Performance steering wheel features a yellow 12 o'clock marking, too.

How fast and economical is the Mercedes-AMG GLA 45 S?

Although the UK's only option is the S, there is a 'regular' GLA 45 with 387hp - reaching 62mph in 4.4 seconds, compared with the 4.3 of the GLA 45 S; this is the same as the previous-generation Mercedes-AMG GLA 45. Top speed is higher on the S as well - it's limited to 167mph, rather than the usual 155mph.

Mercedes-AMG GLA 45 S driving, fast, 2020

Preliminary fuel consumption figures (NEDC converted) suggest a combined average of 25mpg, and CO2 emissions of 210-212/km.

How has AMG achieved this performance?

Squeezing big-power from a 2.0-litre engine has been a longstanding challenge; the UK's 1987 Ford Sierra Cosworth RS500 achieved legendary status with a mere 224hp - even the most extreme was just 260hp. Tuners often claimed more, but reliability invariably suffered.

To get almost twice that output per litre involves installing the engine backwards (in essence) to put the intake at the front of the car, two-stage fuel injection, split-cooling that can control the block and head of the engine separately and much, much more optimisation of every aspect - before Mercedes-AMG's philosophy of one engineer being responsible for the production of the entire engine. For more detail on the Mercedes-AMG M139 engine's technology, read this article on our sister title, CAR.

What this means for you

You can buy a tall, aspirational Mercedes SUV that's small enough for most driveways and parking spaces, yet fast enough to shame most 20th-century supercars, and it's likely to be more affordable than moderately-posh competitors too - a tame-but-luxurious Range Rover Evoque could be more expensive, slower and more anonymous - it's even possible to push a Vauxhall Grandland X to this sort of expense; without the performance or prestige.

Despite the performance potential, it should be as easy to drive as a regular GLA, with the added benefit of four-wheel drive. Though it looks more subtle than the most extreme AMG editions, it effectively signals that you got the most expensive model, too - both visually, and audibly.

Further reading with Parkers:

>> Mercedes-Benz GLA (2020) review

>> What is an SUV?

>> The best small SUVs

Mercedes-AMG GLA 45 S rear view 2020