Skip advert
Advertisement

New Mercedes CLS prototype ride review

On the road in the sleeker four-door Mercedes CLS coupe ahead of its LA show debut

It’s the Mercedes CLS’s blend of comfort and technology that impressed us from the passenger seat. And even with the heavy disguise you can tell this four-door coupe is shaping up to be one handsome car.

The original 2004 Mercedes CLS created a new niche, carving out the four-door coupe sector with its elegant styling and sportier set-up. It’s these elements that Mercedes has elevated to the next level with the third-generation CLS – and we’ve sampled a final pre-production car from the passenger seat in the UK. Here is our verdict ahead of the model’s global debut in November at the LA Motor Show.

Advertisement - Article continues below

This CLS marks the introduction of the new Mercedes 242bhp 2.0-litre four-cylinder petrol engine, but it was the 3.0 straight-six petrol and diesel models we experienced during our ride. The 3.0-litre petrol boasts advanced tech for the brand, too; a new 48V electrical system allows an integrated starter-alternator to deliver a 27bhp hit as part of the new EQ Boost system, totalling 362bhp. These cars can also coast with the engine off to help efficiency.

Best executive cars on sale

On the road, that extra boost was noticeable at low speed, helping to fill in the torque gap until the petrol engine’s turbo was on song. In our test car it revved sweetly with a muted, creamy rasp in Sport+ mode. The nine-speed gearbox is carried over from the E-Class, albeit with recalibrated software here. It shifted nicely, with snappy changes in manual mode and Mercedes’ usual smooth and ultra-refined auto changes in comfort.

The in-line six-cylinder diesels will come in 282bhp CLS 350 d and 335bhp 400 d forms. With diesel it’s all about the torque, so the respective 600Nm and 700Nm mean there’s plenty on tap to match rivals.

Skip advert
Advertisement
Skip advert
Advertisement - Article continues below

Used - available now

4 Series Gran Coupe

2021 BMW

4 Series Gran Coupe

33,000 milesAutomaticPetrol2.0L

Cash £17,995
View 4 Series Gran Coupe
M135i

2015 BMW

M135i

99,989 milesAutomaticPetrol3.0L

Cash £12,995
View M135i
C3

2005 Citroen

C3

35,146 milesAutomaticPetrol1.6L

Cash £3,495
View C3
TRANSIT COURIER

2023 FORD

TRANSIT COURIER

94,000 milesManualDiesel1.5L

Cash £7,495
View TRANSIT COURIER

In 350 d guise the engine felt muscular, with more than enough low-down torque and a suitably subdued rumble, as well as genuine S-Class levels of refinement. A Comfort package with double glazing will be available, and even on 19-inch wheels road noise was nicely suppressed.

Advertisement - Article continues below

The new CLS was comfortable, too, thanks to the extra torsional rigidity of the MRA platform it shares with the E-Class. Three suspension set-ups will be available: passive dampers with steel springs, adaptive dampers and the air suspension system fitted to this test car.

Elements have been tweaked to deliver a target balance of ride comfort with a sportier edge. However, our car felt geared towards the former, with plenty of compliance and a soft but controlled ride. On big wheels over harsh bumps it was a bit unsettled, but the chassis lost composure only a few times on very challenging roads.

The E-Class’s steering has been carried over with no adjustment. Michael Kelz, CLS chief engineer, told us: “It’s something we’re particularly proud of, and we saw no need to change or make it any more direct as it’s not our philosophy.”

Plenty of fancy S-Class features have been adopted, including Energizing Comfort Control – a package that offers different music, climate and massage-seat settings depending on your mood. It also alters the ambient lighting, while the colours of the air-vent surrounds reflect changes in temperature. Autonomous tech will be updated as well, with an improved stop-go traffic function and an overtaking assistant.

Skip advert
Advertisement

Sean’s been writing about cars since 2010, having worked for outlets as diverse as PistonHeads, MSN Cars, Which? Cars, Race Tech – a specialist motorsport publication – and most recently Auto Express and sister titles Carbuyer and DrivingElectric. 

New & used car deals

Omoda 5

Omoda 5

RRP £24,040Avg. savings £1,761 off RRP*Used from £17,995
Dacia Spring

Dacia Spring

RRP £11,990Avg. savings £703 off RRP*Used from £10,000
Renault Clio

Renault Clio

RRP £16,175Avg. savings £3,411 off RRP*Used from £7,500
Volkswagen Tiguan

Volkswagen Tiguan

RRP £38,050Avg. savings £3,637 off RRP*Used from £25,080
* Average savings are calculated daily based on the best dealer prices on Auto Express vs manufacturer RRP
Skip advert
Advertisement

Most Popular

Luxury electric SUVs aren’t selling, and I know the reason why
Opinion - Lotus Eletre

Luxury electric SUVs aren’t selling, and I know the reason why

Deputy editor Richard Ingram thinks luxury SUVs are better suited to PHEV and range-extender tech than pure electric power
Opinion
2 Sep 2026
New Range Rover Electric revealed: How far does it go? How much is it? And why is it so late?
Range Rover Electric driving

New Range Rover Electric revealed: How far does it go? How much is it? And why is it so late?

After what seems like a very long wait, the Range Rover Electric is finally upon us, with full details out in the open and prices from £154k
News
1 Sep 2026
New Toyota Yaris Cross facelift review: hybrid makes a good case for EVs
Toyota Yaris Cross facelift - front tracking

New Toyota Yaris Cross facelift review: hybrid makes a good case for EVs

Toyota’s mini hybrid SUV will cost pennies to run, but the purchase price is thousands of pounds more than several rivals
Road tests
3 Sep 2026