Mercedes CLS 450
speed limited to 155mph.
Crucially, the electric assistance system adds a huge amount of extra torque – 250Nm to be precise and that doubles the pulling power, giving great mid-range operation.
The real benefit comes with fuel economy and the system is capable of ‘sailing’ – that’s running the car with the combustion engine idle when cruising.
Officially the CLS 450 is rated at 36.2mpg with emissions of 184g/km – a significant improvement over the other 3.0-litre petrol model in the range, the Mercedes-AMG CLS 53.
And that is no idle boast. On our run in the CLS 450 we managed to exceed the official figure and saw an average of 36.6 to the gallon recorded on the trip computer.
Externally, the CLS 450 is no different to the rest of the CLS line up and the only real tell-tale that it has EQ Boost is with the instrumentation where there is an EQ power gauge at the bottom of the rev counter and a slightly different readout on the trip computer.
Mercedes has just updated the CLS range which now starts from £57,510 for the diesel powered CLS 350 d. The CLS 450 comes in just above and is priced from £57,460.
All models come with the Mercedes 4MATIC all-wheel-drive system as well as a nine speed automatic transmission.
The CLS 450 we tried came in at £64,260 with extras fitted including a Premium Plus pack which added a Comand online system with 12.3inch display panel, a surround sound system and a 360 degree camera system.
It also came with a Driving Assistance Plus package that included active blind spot and evasive steering assistance as well as a semi-autonomous lane keeping and changing system.
All UK models come in AMG Line trim which includes 19-inch alloy wheels, leather upholstery and an active suspension system.
The petrol versions have a 17.5 gallon fuel tank which reduces boot space to 490 litres from the 520 litres available in the diesels which have a smaller tank at 14.5 gallons.
As such, the CLS 450 should have a range of more than 600 miles and it remains a supremely stylish coupe-cum-GT with powertrain technology that is sure to be seen on other Mercedes models.