Skip advert
Advertisement

Mercedes SL400 2014 review

New twin-turbo V6 kicks off flagship sports car range

Find your Mercedes SL
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 entry point to Mercedes SL ownership is now better than it ever was. In fact, it makes recommending the SL500 that much harder. The SL400 is still not the car for everyone – it feels too comfortable and removed from the action to be called a sports car in the same vein as the 911. But if comfortable cruising is your thing, it’s an excellent choice.

Advertisement - Article continues below

The SL350 is out and the SL400 is in as part of a new line-up for Mercedes’ flagship sports car. A 329bhp 3.0-litre twin-turbo V6 replaces the old 3.5 naturally aspirated engine, providing 27bhp more power for the same price. 

As a result the 0-62mph time drops from 5.9 to 5.2 seconds, giving just the kind of SL performance you want. There’s plenty of torque from low revs and a nice – but muted – exhaust rasp. It all feels less effort than in the old V6.

That easy comfort is what the SL is all about. Our car had Active Body Control air-suspension, which gives a really nice, cushioned ride – the standard springs are nearly as good, too. Over potholes the SL can’t disguise those heavy 19-inch rims sending a jolt into the cabin, but on the plus side it’s just as refined as an E-Class, making for relaxing motorway journeys.

As for handling, it’s on the relaxing side of sporty. It feels planted and predictable, with quick steering. You can’t help but be impressed by how the body stays flat through bends or the tyres refuse to lose grip, but a BMW 6 Series Convertible or Porsche 911 Cabrio are more intense and involving.

Oddly, this engine is no more fuel efficient than the one it replaces – it’s actually a little worse. Economy goes from 37.7mpg to 36.7mpg, and CO2 emissions are up from 169g/km to 178g/km. That’ll cost an extra £55 in road tax for the first year, but otherwise it’s a marginal difference.

With leather, sat-nav, parking sensors, heated seats and xenons, the £72,500 SL400 costs about the same as a 640i Convertible and £15,000 less than a 911 Cabrio. It’s not quite as much fun as either, but for comfort, refinement and style, the SL has got both licked.

Skip advert
Advertisement

New & used car deals

Mercedes SL Class

Mercedes SL Class

RRP £110,930Used from £71,990
Volkswagen Polo

Volkswagen Polo

RRP £15,270Avg. savings £1,925 off RRP*Used from £6,777
Volkswagen Tiguan

Volkswagen Tiguan

RRP £38,050Avg. savings £3,360 off RRP*Used from £11,214
Dacia Spring

Dacia Spring

RRP £14,995Avg. savings £3,565 off RRP*
* Average savings are calculated daily based on the best dealer prices on Auto Express vs manufacturer RRP
Skip advert
Advertisement

Most Popular

Vauxhall Grandland vs Renault Austral: Britain against France in a hybrid SUV clash
Vauxhall Grandland and Renault Austral - front tracking, header image

Vauxhall Grandland vs Renault Austral: Britain against France in a hybrid SUV clash

Renault’s Austral and Vauxhall’s Grandland have both been updated, but which is the better choice?
Car group tests
18 Apr 2026
Used Volkswagen ID.5 (Mk1, 2022-date) buyer’s guide: huge depreciation makes EV very attractive
Used Volkswagen ID.5 - front

Used Volkswagen ID.5 (Mk1, 2022-date) buyer’s guide: huge depreciation makes EV very attractive

A full used buyer’s guide on the Volkswagen ID.5 coupe-SUV that’s been on sale since 2022
Used car tests
19 Apr 2026
New Delivan van brand to launch as Chery targets Ford Transit and VW Transporter buyers
Delivan teaser

New Delivan van brand to launch as Chery targets Ford Transit and VW Transporter buyers

Chery’s new delivery van brand is called Delivan, we can see what they did there
News
16 Apr 2026