Four-door feud: BMW 5 Series vs Mercedes E-Class

First blood goes to the Mercedes, because its larger battery (19.5kWh plays 18.7kWh) lets it convince the authorities that it can go farther on a charge and is therefore worthy of a lower tax burden. In reality, however, it proved less efficient on electric power than the BMW, and both cars’ batteries clocked out after 60 miles.

That’s still a figure that beats early electric cars and could be enough for owners to do nearly all of their daily mileage using only electricity.

It does seem like BMW has its electric ducks in a slightly neater row, because in its EV mode the 530e is not only more efficient but also more intelligent than the E300e.

When you set off on a 200-mile drive with a full battery, the BMW will strategically use the electric power so it depletes the battery by the end, but it retains some electric power for traffic queues and town driving. The Mercedes is claimed to do the same, but in practice just uses up its charge at the start.

While we’re on the hot topic of PHEV running costs, let’s get this out of the way first: you’re vanishingly unlikely to achieve the quoted WLTP fuel economy figures, but an overall mile-per-gallon figure for a PHEV is meaningless anyway, because it’s so dependent on how much of your driving you can do on electricity.

What you need to know is the economy figure when they’re running on electric (3.0mpkWh for the Mercedes, 3.3mpkWh for the BMW), and that both of them can still manage around 40mpg when their batteries run out. If you know roughly how much you will use each power source, you can work out how much they will cost you to run.

You don’t have to be an accountant to drive a plug-in hybrid, but it certainly helps.

With the numbers covered, let’s turn to the question of whether there’s still some joy to be found in these 300bhp rear-wheel-drive saloon cars. And the short answer is yes, there is.

There’s something fundamentally right about sinking down into the mildly sporty seat of a rear-wheel-drive executive saloon, one in which you’re not sitting raised up on a couple of inches of battery pack.

The BMW’s seat goes down lower still than the Mercedes’, but both offer a purposeful legs-outstretched driving position, with a satisfying view over a long bonnet.

They’re both purely rear-drive, too, and they make good use of that. They’re nicely balanced, tightening their cornering lines on the throttle and letting you get into a flow on a twisty road with naturally weighted steering systems that have a build-up of weight as grip levels change.

When it comes to ride quality, both the BMW and the Merc are crying out for adaptive suspension, or simply more compliant passive options, although it applies to the 530e more than the E300e.

The adaptively suspended 550e rides fluidly, but the 530e, well damped though it may be, fidgets continually on its passive M Sport suspension, and on the motorway that gets rather tiresome.

The E-Class feels more ordinary: also a touch over-firm and a bit ragged over bad asphalt but calmer at higher speeds over long distances.

Anyway, the differences between the BMW’s and Mercedes’ chassis are ultimately a question of nuance rather than absolute superiority; where they start to diverge is inside. 

These cars have always been tech showcases, and while in 1990 that meant a digital fuel consumption readout and electric seats, in 2024 it means touchscreens – but with two distinct approaches. 

The BMW maintains the iDrive concept with a rotary controller and some shortcut buttons, which sounds like it should be easier to use on the move than Mercedes’ wall-to-wall touchscreen.

However, while a certain action might take just two taps in the Mercedes, it often takes many more actions in the BMW because of its convoluted and overloaded menu structures. Want to reset the trip computer? Good luck.

BMW has also stripped all the tactility from the physical controls it still has, so you need to look down to operate them – and that is much more distracting than pressing a screen right in front of you.

Mercedes’ control layout is by no means perfect, but I shouted at it a lot less than I did at the BMW’s, and on the whole, not eliciting rage is quite a desirable quality in a luxury car.

The E-Class further pulls ahead with the quality of its interior materials. Where it seems to largely halt the slipping standards in Mercedes cabins, the 5 Series seems to kick it off at BMW.

That the decorative speaker grilles are laser-cut metal in the Mercedes and plastic in the BMW is the most obvious, but the 5 Series’ very plain window switches, swathes of gloss black and clear plastic and the unsubstantial and plasticky gear selector show BMW is on a hardcore cost-cutting drive. While the E-Class is guilty of some of these sins, it grates more in the BMW.

The Mercedes’ interior ambience feels slightly more cohesive, then, but it’s just as bad as the BMW for interior space. Both these cars take up a lot of space on the road, but from the inside you might wonder where it’s all gone.

For a car that is almost synonymous with taxis, rear leg room in the E-Class is unspectacular, and it’s even worse in the BMW. It’s baffling that a six-footer can’t sit behind another one in this five-metre-long car without their knees touching the back of the front seat ahead of them.

At least the 530e’s boot is unaffected for being a plug-in hybrid. That can’t be said for the E300e, which loses a whopping 170 litres compared with the diesel. You’ll know whether boot space or rear leg room matters more for you, but on overall usage of space they’re both losers.

If plug-in hybrids have come of age with regards to their powertrains, then they are still compromised in their packaging and the way they handle their considerable kerb weight.