Skip advert
Advertisement
In-depth reviews

Mercedes CLS review - MPG, CO2 and Running Costs

The CLS is pretty economical for such a large and luxurious car, but insurance premiums are high

MPG, CO2 and Running Costs rating

4.0

How we review cars
Find your Mercedes CLS
Compare deals from trusted partners on this car and previous models.
Or are you looking to sell your car?
Value my car
Fast, no-nonsense car selling
Value my car

The third-generation Mercedes CLS features the firm’s latest and greatest six-cylinder engines. While every new Audi A7 features 48v mild-hybrid tech, the entry-level CLS 350 d and 400 d feature no form of electrification. Despite this, they should be relatively affordable to run – with both managing close to 50mpg. 

Advertisement - Article continues below

The most economical model is the CLS 350 d, which Mercedes claims will do 48.7mpg. The more powerful 400 d will do 47.9mpg, while both emit only 156g/km of CO2 – falling into the 36 per cent Benefit in Kind (BiK) tax band.

The CLS 450 petrol model uses a new 3.0-litre in-line six-cylinder engine with EQ boost technology. This uses an Audi-style 48-volt starter generator and lithium-ion battery to boost power by up to 22bhp for short periods of time. It’ll do 36.2mpg, while emitting 184g/km of CO2. 

An AMG CLS 53 model tops the range for the time being, and by using the same 48v tech will return 32.5mpg and 200g/km of CO2. A nine-speed transmission is standard across the range.

Insurance groups

Insurance groups for the latest Mercedes CLS haven’t been announced yet, but due to its desirability, long kit lists and high prices, we expect the new car to command large annual premiums. For reference, the old Mercedes CLS 350 d AMG Line sat in group 48 – just two groups from the top.

Depreciation

The Mercedes CLS has always been a desirable car, but its high list prices mean you’ll suffer heavy depreciation when it’s time to sell. While it’s better than the old car (residual values ranged from 32 to 35 per cent), no new CLS retains more than 44 per cent of its value after three years or 36,000 miles.

The strongest performer is the CLS 400 d AMG Line (43.7 per cent), while the worst is the CLS 450 AMG Line with the Premium Plus pack fitted (39 per cent). The popular 350 d sits somewhere in between the two.

• Best low emissions green cars

The all-new Audi A7 is no better, however, as all versions are expected to retain between 38 and 39 per cent of their value over the same timeframe.

Skip advert
Advertisement

New & used car deals

MG MG4

MG MG4

RRP £26,995Avg. savings £8,094 off RRP*Used from £13,199
Toyota Yaris Cross

Toyota Yaris Cross

RRP £26,495Avg. savings £1,879 off RRP*Used from £15,633
Nissan Juke

Nissan Juke

RRP £19,785Avg. savings £3,331 off RRP*Used from £10,000
Vauxhall Corsa

Vauxhall Corsa

RRP £18,725Avg. savings £4,199 off RRP*Used from £15,337
* Average savings are calculated daily based on the best dealer prices on Auto Express vs manufacturer RRP
Skip advert
Advertisement

Most Popular

Chinese cars can’t match their European rivals when it comes to engineering
Opinion - Shanghai Auto Show

Chinese cars can’t match their European rivals when it comes to engineering

This new brand of cars might have battery tech on their side, but European buyers want much more than that
Opinion
25 Apr 2025
Buying a modern used car for under £10k is almost impossible
Opinion - £10k used cars

Buying a modern used car for under £10k is almost impossible

Phil McNamara discovers that it’s harder than ever to find a good-value car at the affordable end of the market
Opinion
24 Apr 2025
Leapmotor B05 family hatch on route to the UK with sub-£30k price and 400-mile range
Leapmotor badge

Leapmotor B05 family hatch on route to the UK with sub-£30k price and 400-mile range

The Stellantis-backed brand will launch a Volkswagen ID.3-rivalling small car with almost 20 per cent more range
News
23 Apr 2025