The arrival of a new 5 Series is always big news in the executive car world. It can spell trouble for BMW’s rivals, though.

As if to back that up, the 5 Series that’s all-new for 2017 has just been named What Car? magazine’s Car of the Year. So the Mercedes-Benz E-Class, itself less than a year old, has its work cut out.

We have the E 220 d SE here, against the 5 Series 520d SE. That’s a brace of 2.0-litre diesel engines; Merc’s is mated to a nine-speed auto box, while BMW’s has the eight, and both work very well to enhance the air of steady calm within the cabin.

In each case, when ensconced behind the driver’s wheel you could be in the next car up. The E-Class certainly has an S-Class vibe to it, and the 5 Series is loaded with features first seen on the latest 7 Series.

There’s a greater air of eye-appeal to the Merc, especially with the Comand media and 12.3” wide-screen display added as options (budget £2000 for that). It looks superb. But the 5 Series has the edge in terms of feel and class, and though Merc’s media set-up is good there’s still nothing like BMW’s iDrive system – whose pin-sharp 10.2” display now makes it better than ever.

Further standard kit on both models includes cruise, climate, leather, seat heaters and parking assist. Both also have autonomous emergency braking, while the E-Class features LED headlamps. As for space, both have lots; Merc is a little more generous to rear-seat passengers, while BMW gives you better access to the 5 Series’ boot.

The other kind of boot gets you going with suitable pace, and once moving the 5 Series takes the lead through corners with a fine blend of braking and body control. It’s more comfortable overall, too, even on optional 19” rims which made our test car fidget on imperfect surfaces, as the E-Class’ softer suspension is more easily upset by pot holes and crests in the road.

Neither car will stun you with its steering feel in corners, it must be said. However both are well set up for high-speed stability, which is of course exactly as they should be.

One possible drawback with the new 5 Series is that it looks so much like the old one. People who know their BMWs will recognise it, of course, and it could be that you’re not interested in impressing anyone else, but if snob appeal matters both this and the E-Class’ more imaginative interior design might sway you Merc-wards.

If you do, it’ll cost you a touch less to run as a company car, though not enough to sway you if the BMW is the one you really want. Leasing and ownership costs are on Merc’s side, too; over the course of three years, a private buyer can expect this E-Class to cost £2700 less than the equivalent 5 Series.

If you’re buying the new 5 Series, we’d recommend speccing the VDC adaptive suspension on our test car – but not the 19” alloys. That way, you’ll get the best ride the car can offer – which ought to be very good indeed.

Go for an E-Class with the cabin upgrades we mentioned above, and you’ll get a superb executive car. But for a bit more money, you can get an executive car that’s beyond superb – it’s one of the very best cars there is in any class. BMW has done it again.

BMW 520d SE

Engine size 2.0-litre diesel

List price £36,025

Target price £35,485

Power 188bhp @ 4000rpm

Torque 295lb ft @ 1750rpm

​0-60mph 7.8sec

Top speed 146mph

​Gov't fuel economy 68.8mpg

True MPG 43.5mpg

CO2 emissions 108g/km

Mercedes E 220 d SE

Engine size 2.0-litre diesel

List price £36,230

Target price £33,207

Power 191bhp @ 3800rpm

Torque 295lb ft @ 1600-2800rpm

0-60mph 7.5sec

Top speed 149mph

Gov't fuel economy 72.4mpg

True MPG 44.8mpg

CO2 emissions 102g/km