BMW 4 Series Convertible vs Mercedes E-Class Cabriolet

It's great when the weather dictates a wide-brimmed hat instead of a waterproof one. Now that summer is here, BMW has the new 4 Series Convertible to tempt you into that sun-kissed roof-down drive in the country.

Would the BMW be your best option, though? After all, the Mercedes-Benz E-Class Cabriolet is one of our favourite drop-tops, and it has been revised to make it even more appealing. So, which keeps you looking calm, collected and, above all, cool?

What are they like to drive?

Both engines are punchy enough for keeping pace with fast-moving traffic. The Mercedes’ diesel engine pulls from slightly lower revs (around 1400rpm), but the BMW isn’t far behind, and its extra 14bhp means it can ultimately accelerate more briskly.

The BMW’s engine is certainly noisier, though; it can be heard more clearly than the Mercedes’ when worked hard, and you also feel slightly more vibration through the pedals.

The 4 Series in our pictures was fitted with a six-speed manual gearbox, but the optional eight-speed Sport automatic ’box is the better choice, and is more accomplished than the E-Class’s auto ’box. The BMW’s auto is smoother and chooses the right gear more of the time. It also responds faster when you use the steering-mounted paddles. 

The 4 Series handles more sweetly, too. It turns in to corners more sharply and controls its body movements better through tight twists and turns. It also has the quicker, more accurate steering, although the Merc’s still gives you plenty of confidence as you turn in. 

Our 4 Series was fitted with adaptive M Sport suspension (a £750 option), which allows you to make it stiffer or softer at the touch of a button. The E-Class, on the other hand, gets adaptive suspension as standard, although it adjusts automatically depending on the type of driving you’re doing; you can’t override the car’s choice.

Adaptive it may be, but the Mercedes’ suspension is always softer than the BMW’s, so it’s more forgiving over big bumps and smooths out most minor scars. However, there’s no getting away from the fact that the Merc’s body isn’t as rigid as the BMW’s; it shimmies and shudders more at low speeds over broken surfaces.  

Roof up, the BMW kicks up more road noise at a cruise, which is more of an irritation than the fact there’s marginally more wind noise in the E-Class.

Fold down the roof and the Mercedes remains the more refined car. Those in the front are better sheltered from wind, and the E-Class’s standard Aircap system effectively deflects wind over rear passengers. 

Achieving the same calm in the front of the BMW requires you to spend an extra £265 on a large wind deflector, which sits across the rear cabin, effectively turning the 4 Series into a two-seater; travelling four-up in the BMW with the hood down is a blowy experience for all concerned.

What are they like inside?

Even tall drivers will find it easy to get comfortable in either car, because there’s a wide range of adjustment in driver’s seats and the steering wheels. They’ll have no issues with headroom either. 

It’s a pity that neither car gets adjustable lumbar support, but the E-Class’s front seats are more supportive than the BMW’s in standard form. 

Getting into the back is easy enough in both cars, but once you’re in there you’ll see there isn’t much legroom. The BMW is marginally better in this respect, and it has slightly more shoulder and headroom.

The boot in either car will swallow a set of golf clubs or a small buggy – when the roof is up. However, folding down the Mercedes’ fabric roof reduces boot space only slightly, whereas the BMW’s loses much more space because its metal hood concertinas into the boot.

Both cars get ski hatches as standard, which makes loading long items easier. For an extra £170, the BMW is also available with split-folding rear seats, which aren’t available on the E-Class. 

Both dashboards look smart enough, although the materials used in the 4 Series feel slightly classier and its infotainment system is also more intuitive with user-friendly menus that you scroll through using a rotary dial between the front seats. 

The Mercedes gets the same style of controller, and a larger standard colour screen, but its three-layer menu system is trickier to navigate. 

What will they cost you?

The 4 Series has the cheaper list price, but go in search of discounts and you’ll spend less on the Mercedes; a price cut of more than £5000 means it will cost you £1700 less to buy. 

The E-Class is also predicted to hold on to more of its value for longer, so even though it’s a bit more expensive to insure and service, it’ll still work out around £1800 cheaper over the first three years.

The opposite is true if you’re a company car driver, though; the E-Class sits in the same tax band as the 4 Series, but its higher list price means 40% rate taxpayers will have to pay £150 more each year in company car tax. 

Both cars get 17-inch alloys, electric (and heated) leather seats, climate control, auto wipers, cruise control, DAB, Bluetooth and a USB socket. The Mercedes even gets sat-nav as standard, which costs £890 on the BMW.

Euro NCAP hasn’t crash-tested either car, but the Merc has more airbags (seven to the BMW’s six) and it offers rear side ’bags as an option. The BMW doesn’t.

Our Verdict

The 4 Series puts up a strong fight. In fact, it’s more fun to drive than the E-Class, more comfortable at low speeds and has a bit more rear headroom.

However, it’s simply not as good a drop-top as the Mercedes. The E-Class isn’t just better at protecting occupants (front and back) from wind buffeting, it also has the bigger boot – especially with the roof down – rides more comfortably on the motorway, is better equipped and is cheaper to own.

Mercedes E220 CDI Cabriolet SE Auto

For More refined engine; less buffeting; bigger boot

Against Uninspiring handling; less settled ride

Verdict Comfortable, refined and well-equipped. Still a great drop-top

BMW 420d Convertible SE Sport Auto

For Impressive handling; quality cabin; iDrive control system

Against Noisy engine; blowy in the back; small boot with roof down

Verdict Fun to drive, but not the best drop-top