Road Test: Mercedes-Benz E Class E250 D 4dr Auto

Mercedes likes to make a song and dance about the heritage of the E-Class by dotting the brochure with photos of museum-standard examples of its 60 years'-worth of predecessors. For a more concrete demonstration, though, go to Berlin. Almost all the taxis there are mid-size Benzes, and many of the older ones came over from Frankfurt and Hamburg when Germany was reunified. In a few days there, I rode in a vertical-headlamp one, the later W123 and W124, as well as the two more recent four-lamp generations. All painted the same shade of beige. All still rolling along nicely despite the zillions of km on the clock.

But Berlin cabbies aspire to a new vehicle. Over the past few years, they've been clubbing together in threes to fund shared E-Classes which they run on three shifts, 24 hours a day. It's not uncommon for one of those cars to rack up 120,000 miles a year. All in town traffic. Imagine the number of starts and stops that is. The number of slams of the rear doors. The number of passengers clumping down on the seat cushions, and a few minutes later, hauling themselves out by the grab handles.

Mercedes' test department has put the new E through this work cycle, and the guys are confident. They've also engineered it to do thousands of miles flat-out round the Nürburgring. Fully loaded. So I think we can be confident of its durability. It certainly feels as strong as granite.

The E-Class is the epicentre of the Mercedes brand, and so of all the things it has to be, the clear number one is that it has to be solid. Solid as in unbreakable, safe, respectable and conservative. If you want excitement and frivolity, you've come to the wrong place. The only thing about it that aims to tickle your fancy is the slightly over-ornate exterior styling, and I'm not a big fan. The front end seems confused; the back, derivative. The side view is fine, though, and I can see it working well as an estate - we'll know later this year.

Almost nine out of 10 Es sold in Britain last year were diesels, and I can't see that reversing with the new one. There's a staggering new diesel engine on offer. It's only 2.15-litres and comes in various outputs as the E200/220/250CDI. The E250CDI version kicks out 204bhp and will do the 0-62 thing in just 8.2secs. If you think 200bhp-plus is good for a 2.15-litre four-cylinder diesel, consider that the torque figure more or less matches Merc's mid-1990s 6.0-litre petrol V12. And yet it does better than 50mpg in the EU test. The E250CDI's outputs are actually embarrassingly close to the V6 E350CDI's.

Sure enough, the torque wave will scoop you up and propel you like a little firework. A series of fireworks, in fact - you have to change gear fairly often, despite the promise of a wide torque spread from two sequential turbos. Most will buy the auto, which is smooth but has only five speeds (V6 Es get the 7G-TRONIC) and has a big gap between 2 and 3.

Of course, something has to give. As often happens with diesels at the sharp end of the performance-emissions compromise, refinement suffers. The E250CDI isn't exactly crude, but it is loud, rumbling away audibly, even at a steady cruise. But then you notice it because the rest of the car - tyres, road noise, wind woosh - is very quiet.

There's not much wrong with the suspension and steering. In fact, most of the hardware is now shared with the C-Class, a car we like a lot. The steering is accurate, and the car feels terrifically stable. It's reasonably well-planted through corners too, but not actually a whole barrel of laughs. Even when I had a go in the 388bhp E500, things remained po-facedly well-controlled. Great for very long journeys, not so great for hooning about. Solid, in fact.

But I like it for that. Because the E knows what it is, and you have to be prepared to acknowledge what you are. The hollow ring of false sportiness is banished. In return, you're given superb ride comfort, both at low speeds or on lumpy A-roads. It's even better on the optional air suspension, but the steel coils are fine enough. Which is really what it's all about for most people who buy these cars: they're not going to be smoking the tyres. They'll be commuting, or doing long trips. Or, like those Berlin co-ops, doing lots of short ones with a fare out back. 

The E-Class remains boxy: Benz has the CLS for being swoopy. So there's huge space in the E, a sitting room on wheels. Every detail of the ergonomics is worked out to the last detail to make life easier on a long trip, and you could sit, ache-free, in the front seats until supplies of foodstuffs and water ran out. The materials, at least in the top models, are pretty lush. Yet the overall impression is serious and workmanlike. This is more like an upgraded C-Class - there are few of the S-Class's magical luxury touches. 

But again, that's what the E is like. Efficient and sober at the expense of magic or frivolity. Almost the entire engine range has switched to four-cylinder - apart from those three 2.1-litre diesels, there is also a set of brand-new 1.8-litre turbo petrols with outputs of 184 (E200CGI) and 204bhp (E250CGI). Everything except the E500 and E63AMG comes with BlueEfficiency, a package of tweaks to aero, rolling resistance, weight and powertrain to cut consumption and CO2. But even a Merc engineer admitted that the four-cylinder E250CGI engine isn't as refined as the V6 it replaces, though the economy and torque are better. 

If you pay extra, you can have an E with all manner of electronic safety aids, including radar cruise (Distronic PLUS) self-braking collision mitigation (BrakeAssist PLUS) and watchdogs to make sure you don't drift out of your lane or hit another car that's in your mirror blind spot. For the dark, you can have night vision. A standard feature is a setof monitors looking at the way you drive, and if you get erratic because you're tired, it flashes up a steaming cup in the speedo matrix display. They should have called it KaffeeTRONIC. It won't operate for the first 20 minutes of a journey, as it takes that long to get the measure of your style - you might drive erratically all the time. In fact, if you do, I think I've been in your taxi.

All the time I was in it, I admired the E-Class more and more, but you know it isn't really a thing that'll ever seduce you. It's so fabulously well-targeted at the real world, at the way most people drive rather than the ‘sporty' way they like to think they drive. It gets the job done with efficiency and comfort and safely. I wish we needed a frivolous big saloon in 2009, but sadly we don't. This one hits the mood of the day.