New Alfa Romeo Giulia Quadrifoglio vs new Mercedes-AMG C63 S

Both of these high performance saloons produce more than 500bhp, and both have recently been updated. Let's see which is the better buy...

Alfa Romeo Giulia Quadrifoglio vs Mercedes-AMG C63

The contenders

Alfa Romeo Giulia Quadrifoglio

List price £67,195
Target Price £65,258

This three-time winner of our Performance Car of the Year Award has been treated to some upgrades, notably in the area of interior quality

Mercedes-AMG C63 S

List price £76,903
Target Price £72,448

AMG’s thunderous V8 C63 has been fettled significantly in the time it’s been on sale, but does it have what it takes to leapfrog its Italian rival?

Remember the saying ‘speak softly and carry a big stick’? Well, the Alfa Romeo Giulia Quadrifoglio and Mercedes-AMG C63 are the automotive embodiment of that sentiment. At first glance they look like executive saloons with the option box for the biggest wheels possible ticked, but in reality they are far removed from the snails in leopard costumes you see pounding up and down motorways across the land.

For starters, both of these super-saloons pack a mighty 503bhp – enough for performance that would suit a supercar, let alone something with room for five and some luggage. Of course, their prices reflect their range-topping status, and neither exactly sips unleaded. But look at them another way: by combining sports car speed and agility in sensible packages, they remove the need for a second car that’s just for fun. That sounds like a semi-sensible way of saving money to us.

Alfa Romeo Giulia Quadrifoglio rear

With this logic in mind, let’s take a closer look at our contenders. The Giulia needs little introduction, having won our Performance Car of the Year title three years in a row between 2018 and 2020. Now facelifted, it’s time to put it back through the wringer. And with the latest BMW M3 not yet in showrooms, the C63 is the Guilia’s key rival. Not only does it match the Giulia’s muscle, but it, too, has been fettled and facelifted since we last tested it.


Performance, ride, handling, refinement

It’s amazing how different two super-saloons can sound. The C63’s big 4.0-litre twin-turbocharged V8 is easy on the ear regardless of how quiet you’ve set the exhaust. By contrast, the Giulia’s more highly strung 2.9-litre twin-turbo V6 has a gritty snarl when the rev counter’s needle soars towards the red in Dynamic or especially Race mode, but sounds more like the three-cylinder motor from a city car when you drive it gently in the more relaxed settings.

The two cars also deploy all that power differently. With its launch control system engaged to help manage wheelspin, the C63 managed a seriously rapid 0-60mph time of 4.1sec, with 0-100mph on our private test track taking a mere 8.6sec. However, even without the benefit of launch control, the Giulia actually proved significantly quicker; it managed 0-60mph in a lightning 3.7sec, with 0-100mph taking 8.0sec dead.

Mercedes-AMG C63 S rear

It’s a similar story when you're rolling, with the Giulia pulling just ahead of the C63 when sprinting from 30-70mph. That said, anyone who thinks the C63 feels a bit slow – even if they drive it after the Giulia – has a screw loose.

Besides, straight-line speed isn’t everything, and the C63 really lives for corners. Pitch it into a bend and, while you’ll find its steering isn’t quite as quick as its rival’s, it has a more reassuring heft and communicates the tyres’ interaction with the road surface in more detail. Regardless of how firm you set the Giulia’s adjustable suspension, the more stiffly sprung C63 exhibits a little less body lean and feels keener to dive into a bend.

It’s happier on the exit, too; the Giulia will sometimes allow an inside rear wheel to spin when accelerating away from a corner, before clumsily shuffling power to provide more traction. That’s never an issue with the C63, which delivers its power in such a way that you can accurately steer with the accelerator pedal.

Alfa Romeo Giulia Quadrifoglio front

To attempt the same in the Giulia requires that you engage Race mode, and because doing so will fully disengage the traction and stability control systems, it’s something that we wouldn’t recommend doing on the public road. We advise similar caution in the C63, of course, but cranking that car up to its angriest mode still allows a degree of electronic intervention, providing a safety net to help if things get properly out of shape.

Of course, you’re not going to drive everywhere like you’re lapping Silverstone, so what are these cars like when you’re just popping to Waitrose? Well, on trips like these, the Giulia’s softer suspension pays dividends by smothering imperfections more effectively, especially in Comfort mode, but you’ll be aware of vertical movement on undulating roads.

Switch to the firmer C63 and the road’s topography is rendered in greater detail, but it controls body movements better while still making a decent fist of taking the edge off sharp intrusions.

Mercedes-AMG C63 S front

The Giulia is more subdued to travel in, though. Sure, there’s a bit of wind and tyre noise, plus a bit of exhaust blare, but the C63 does less to mute the roar kicked up by its tyres, and the optional panoramic sunroof (part of the £3114 Premium Plus Package) generates a bit of wind whistle.

Although the Giulia’s brakes are ultimately slightly better than the C63’s when it comes to outright stopping power, the latter car’s brake pedal has more feel and makes it easier to gauge how much pressure to apply for a graceful stop. On the other hand, the Giulia’s gearbox is the smoother of the two, while also being able to fire gearchanges home as swiftly as you’d want in its sportiest driving modes.

What are they like inside? >>

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