Audi S4 vs Mercedes-AMG C 43

In the past, if you wanted a fast saloon car that slipped under the radar, the original Audi S4 would have been top of your list.

Over time, the brand’s S models have been endowed with more bling and aggressive road presence, but now this latest S4 has gone back to its more understated beginnings.

• Best performance cars

Mercedes-AMG has also developed a sporty saloon to sit underneath the ballistically quick, range-topping C 63. Called the C 43, it matches the Audi’s V6 turbo engine, auto box and four-wheel-drive system.

Both are priced around £45,000, but with stats as close as these, where do the differences lie and which comes out on top?

Head-to-head

 Audi S4

31

• • For: Effortlessly quick, hi-tech cabin, impressive build quality.
• • Against: Fast but not very inspiring to drive, firm ride, pricey. 

Styling is a big factor in the world of performance cars, but there are no big wings or gaping air vents here. The new S4’s chrome twin-bar grille, satin-finished silver mirrors, understated boot-lip spoiler and quad exhaust pipes are the only hints at the performance potential on offer, because Audi has focused on a more reserved design for this model.

However, there’s nothing understated about the performance. Audi’s Drive Select system lets you tailor the car’s settings to your tastes or chosen mood, so in the sportiest Dynamic mode the S4 is sharper and tauter to drive. In this setting, throttle response is better, but there’s still a little turbo lag as the engine fights against the gearing and the S4’s 1,630kg kerbweight. This is also partly due to the eight-speed auto’s long ratios.

Used - available now

2020 BMW

5 Series

29,101 milesAutomaticPetrol2.0L

Cash £19,100

View 5 Series

2023 Kia

Sportage

33,560 milesManualPetrol1.6L

Cash £20,300

View Sportage

2022 Volvo

S90

74,484 milesAutomaticPetrol2.0L

Cash £22,197

View S90

2022 Mercedes

EQA

28,141 milesAutomaticElectric

Cash £20,697

View EQA

Once the engine is into its stride, though, it pulls strongly, accelerating between 50 and 70mph in seventh gear in 6.3 seconds. Eighth drops the revs right down for cruising, so the S4 took 9.8 seconds over the same test – 2.4 seconds more than the C 43.

Our car was fitted with the £1,200 optional electronically controlled quattro Sports limited-slip rear diff that makes the S4’s cornering attitude a little more adjustable on the throttle. There’s also a system that automatically brakes the inside wheels to aid cornering performance, but from behind the wheel, it all feels very calm and controlled. Too controlled, in fact, so while it’s great for safety, it feels a little inert and flat, even at the high speeds the S4 can hit in less than perfect conditions.

31

While the styling and driving experience are more reserved, the ride definitely isn’t. Our car was fitted with £550 optional 19-inch alloys as well as the £900 adaptive sports suspension. Even in Comfort mode the S4 is firm, thumping over bumps as the dampers struggle to absorb B-road imperfections. Over smoother tarmac it’s better, but even small ridges cause the car to fidget gently.

The steering is responsive, though; there’s very little feel, but in Comfort mode, the weight is lighter than the Dynamic setting, so the steering feels more transparent as a result.

It’s difficult to criticise the S4’s cabin, which is spacious and comfortable. But despite the quality of the materials and solid build, it feels a little too clinical. At least there’s lots of tech on offer to make living with the S4 easier.

An 8.3-inch screen with sat-nav and DAB, heated leather sports seats, LED headlights with high-beam assist, cruise control, keyless go and all-round parking sensors are all fitted as standard.

Testers’ notes

• • Technology: The 8.3-inch central screen is clear, while the touch-sensitive MMI control wheel in the centre is easy and intuitive to use.
• • Finish: High-quality leather and metal finish give the S4’s interior a classy and expensive feel.
• • Virtual Cockpit: Digital dials on the 12.3-inch screen behind the steering wheel show sat-nav, driving data and multimedia.

Mercedes-AMG C 43 

31

• • For: Lovely exhaust note, exploitable chassis, high-quality cabin.
• • Against: Pricier than S4 even on finance, not as efficient, expensive options.

Mercedes’ warm ‘AMG Sport’ performance variants were rebadged as full-on Mercedes-AMG models at the start of 2016, opening the floodgates for the arrival of a new tier of official AMG machines. As a result, a glut of sub-range-topping performance cars using the ‘43’ badge has hit the market. It’s a familiar nameplate on this bodystyle, though, because the brand applied the ‘43’ tag to its supersaloons in the late nineties.

It brought the badge back last year on a car sitting beneath the top-of-the-range C 63, offering an appealing balance of usability, performance, practicality and prestige. The £45,785 price tag certainly reflects this, but there’s plenty of muscle for your money, because the 3.0-litre twin-turbo V6 outguns the S4. With a fatter 520Nm of torque, compared with the Audi’s 500Nm, it also delivers stronger performance. This showed on test because the C 43 sprinted from 0-60mph in 4.5 seconds.

While the nine-speed auto box wouldn’t let us complete the 50 to 70mph test in top gear, it was quicker than the S4, accelerating over this speed range in eighth in just 7.4 seconds. With one more ratio than the Audi, it means cruising revs in top gear are similar, but with faster acceleration.

The transmission also kicks down more quickly and responds faster to the paddles. Blips on downshifts don’t seem as laboured as in the Audi, with a crisper flaring of revs, while there’s none of the S4’s jerkiness when going up through the gears.

31

Our test car was also equipped with the AMG Performance exhaust. It’s not cheap, at £1,000, but while the C 43 sounds nice as standard, the optional exhaust releases a lovely V6 howl under acceleration, as well as some thunderous cracks and pops when you lift off the throttle. It adds a little to the overall driving experience, too.

As with the Audi, the Mercedes offers adjustable driving modes, ranging from Comfort to Sport and Sport+. But unlike the S4, the C 43 features adaptive dampers as standard, offsetting the price difference.

In Comfort the suspension is more absorbent, controlling the £595 optional 19-inch wheels with finesse. It’s firm, but more supple than the S4.

In Sport+ the dampers keep body roll in check nicely. The tight suspension means you’ll certainly feel the road more over bumps, but this interaction with the chassis is where the Mercedes puts daylight between itself and the Audi.

These are performance cars, and while the C 43 offers a comparable level of kit, quality and practicality to the S4, meaning it’s just as usable, it’s the more engaging fast saloon.

Testers’ notes 

• • Multimedia: Mercedes’ 8.4-inch COMAND system comes as part of the Premium Plus package, and replaces seven-inch display. Sat-nav is standard.
• • Comfort: Bucket seats are supportive and cabin feels cosseting, yet it still keeps sporty touches.
• • Storage: Cabin gets plenty of cubbies and storage, including large door bins and central drawer. 

Verdict 

First place: Mercedes-AMG C 43

31

The C 43 matches the S4 for practicality and prestige, but betters it in terms of ride comfort and dynamic ability. You can sense its AMG character shining through, whereas the S4 isn’t as engaging on a twisty road. So while the Mercedes will cost you a bit more to buy and run, we reckon it’s well worth it. 

Second place: Audi S4

31

The S4 is deceptively fast and nicely understated – but perhaps just a little too much, because it doesn’t offer the fun or involvement of the C 43. These models are matched for practicality, but in this sector, how a car makes you feel is more important, and the Audi simply isn’t quite as special.