The CLS is cutting-edge design that plays to some traditional brand strengths, says Alex Grant.

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With its compact products in order and variants to suit all lifestyles, Mercedes-Benz is continuing to make ‘premium’ accessible and versatile. It’s sold 1.5 million cars worldwide in a record first eight months of 2018, and even challenging market conditions haven’t stopped it ranking among Europe’s best-selling brands.

The CLS is part of that ongoing evolution. It’s not a volume car like the A-Class, but the coupé and executive saloon cross-breed plays to traditional brand strengths, defining a segment back in 2003. It shares a platform with the E-Class, takes styling cues from the latest A-Class, and counts cars such as the Audi A7 and even the Tesla Model S among its diverse rivals.

However, this isn’t just a curvier E-Class. The only four-cylinder option is a 2.0-litre, 245hp four-cylinder fitted with a nine-speed automatic transmission, which emits 142g/km CO2. All other CLS variants feature 3.0-litre six-cylinder engines with four-wheel drive; two ‘mild hybrid’ petrols at 389hp and 457hp, and a pair of diesels producing 286hp and 340hp, both emitting 148g/km.

So, no hybrids. But big diesels still make sense in a car like this, built as it is for covering the length and breadth of the Continent in effortless comfort. The 340hp ‘400 d’ makes easy progress at highway speeds, with almost no wind, road or engine noise, featuring an 80-litre fuel tank to help eat up the miles. Motorway fuel economy of around 4.7l/100km is impressive, and independent testing by Emissions Analytics has shown it’s one of the cleanest diesels on the market, easily coming under the limits set by the Real Driving Emissions Step 2 (RDE2) standard during on-road use.

Inside, it feels like a high-spec E-Class; its dashboard trimmed in artificial leather, accented with aluminium and ash inserts and available with the all-digital instrument cluster that flows into the central infotainment screen. Three-quarter visibility is predictably tricky and the boot opening is narrow, but it’s now a five-seater and two of the three rear-seat passengers have plenty of head and leg room, on a bench which can be folded flat to extend the boot capacity. In polluted areas and tunnels it’ll even switch the climate control to recirculate the air rather than drawing it in from outside.

However, not all of the technology on board stacks up so well. Android Auto and Apple CarPlay are optional and the infotainment feels a generation behind the new A-Class, lacking the augmented reality navigation, which overlays directions over a live image from the front-facing camera. As in the E-Class, the steering wheel trackpad buttons are too sensitive while manoeuvring, and don’t allow track skipping without going into the Media menu on the home screen. They’re details, but persistently    irritating ones.

In fleet, at least, it’s a car that perhaps needs a plug-in or lower-powered four-cylinder diesel, and possibly the old car’s Shooting Brake variant to really drive volume. But for those who can, the CLS shows growing mainstream appeal hasn’t blunted the three-pointed star’s talent for premium.

What We Think:

As big a generational step forwards as the E-Class, the CLS’s only weak points are its limited engine range and tech compared to new A-Class.

Strengths

High-speed luxury with 4.7l/100km fuel economy

Weaknesses

Limited engine line-up, technologically behind the A-Class

IFW Rating: 4 out of 5