A new petrol engine with mild-hybrid technology is the headline addition.

Mercedes-Benz is replacing its V6-powered E 400 Coupe and Cabriolet with a new “EQ Boost” mild-hybrid engine.

Dubbed the E 450, the new engine is a 3-litre inline six-cylinder unit with a 48-volt generator that allows for extra power and efficiency.

Mercedes is going green-ish...

The engine is already available on the larger CLS saloon, and it produces 362 bhp, plus an extra 22 bhp from the EQ Boost motor.

In the E-Class Coupe, it will return 32.1 mpg and manage the sprint from 0-62 mph in 5.6 seconds – although not necessarily at the same time. The Cabriolet is less efficient, but only slightly, returning 31.7 mpg and completing the 0-62 mph dash in 5.8 seconds. Both cars are limited to a top speed of 155 mph by an electronic governor.

2017 Mercedes-Benz E-Class Cabriolet

And the new mild-hybrid engine isn’t the only addition to the E-Class range. The old E 350d All-Terrain, the high-riding off-road estate car, has had its old 3-litre V6 diesel engine replaced with a new inline six-cylinder diesel.

Now with 335 bhp, the new 400d is almost a second faster to 62 mph than the old 350, completing the sprint in 5.4 seconds, rather than 6.2.

The in-car technology has also been upgraded, with a 360-degree manoeuvring camera, wireless phone charging and an Energising Comfort package, which includes air fragrancing, a massage function and ambient lighting.

2018 Mercedes CLS

At the same time, Mercedes has added a new engine to the CLS range. The new 350 model features an all-new four-cylinder petrol engine, which produces 295 bhp. Like the E 450, it has the EQ Boost motor, which adds a further 14 bhp and allows it to get from a standstill to 62 mph in six seconds. It’s also capable of 39.8 mpg and 162g/km CO2 emissions.

All these vehicles are on sale now, with the first deliveries expected in October. The E 450 Coupe costs £50,900, while the Cabriolet costs £55,395. The CLS 350, meanwhile, starts at £52,625 and the E-Class All-Terrain 400d costs £64,445.

Gallery: 2017 Mercedes-Benz E-Class Coupe