The BMW 4-series is the model formerly known as the 3-series coupe. If this seems wilfully confusing, and an obvious attempt to bamboozle the market into accepting a higher price point for a coupe variant, then consider this. BMW is only copying what Audi has already done by creaming the coupe and cabrio off the A4 range to create the A5. You could almost say that Mercedes, by not pulling this trick, has been the most disingenuous of the three. After all, the recently facelifted two-door E-class is in fact based on the ageing C-class, which will be replaced next year. So, from a marketing perspective at least, the three contenders here are a mixed bag. They’re very close in performance, surprisingly varied in ability, and quite different in character. But who wins?
The 4-series coupe concept unveiled at Detroit in January was a brash effort with too much LED bling in the front and enough cavities in the rear bumper to appeal to a dentist’s sense of honour. The production car is, as so often, a rather tame effort by comparison. The M Sport pack looks sufficiently butch, but the Sport Line spec featured here probably won’t soften the spines of the hedgehog inside your wallet. From the rear in particular, this is a mildly modified 3-series with a 435i logo attached. Blame the target customer: he’s a 55-year-old bloke, not a boy racer.
There are some real differences between old 3 and new 4, however. The 435i is bigger, for a start. It’s 16mm lower than the 335i, its wheelbase has been extended by 50mm, the front track is 45mm wider and the rear wheels are an even more generous 80mm further apart than before. At 500mm above terra firma, the 4-series is claimed to sport the lowest centre of gravity of all current BMW models. The suspension has been beefed up and 25kg has been shaved off the kerb weight. So, it’s not mere cosmetics.
But in this market, cosmetics really do count and, although first introduced in 2007, the Audi is still arguably the most attractive of the three. The proportions are spot-on, the design strikes a perfect balance between elegant and extrovert, and the build quality teaches the rivals a lesson or two. The Mercedes we test here features the AMG Sport kit, which is a little too flamboyant when viewed head-on but rather nice when looked at from behind. In terms of street cred, the E400 scores eleven out of ten for the fully retractable side windows which make this car look so cool it almost hurts. We asked Adrian van Hooydonk, chief designer at BMW, why he felt compelled to keep those ugly B-posts when the pillarless drop-top was only six months away. ‘Because the roof must carry the vehicle weight seven times over in a rollover accident,’ he said. ‘Reinforcing the structure would add up to 200kg in weight, and that’s even before we start talking cost.’ And sure enough, the Mercedes carries a 125kg penalty over the 435i.
Looks, of course, are subjective; performance less so. And all three cars are certified quick. The top speed is a governed 155mph across the board, and the acceleration times are also in the same ballpark. From 0-62mph, the Audi (4.9sec) edges the BMW (5.1sec) which in turn pips the Benz (5.2sec). All three engines employ six cylinders, the displacement is an identical 3000cc, and all are forced induction. While S5 and E400 muster 328bhp at 5500rpm, the 435i develops 302bhp at 5800rpm. In contrast, every unit plots its own individual torque curve. Audi opted for the sportiest graph which plateaus from 2900 to 5300rpm where 324lb ft are on tap. BMW seems to favour the middle ground, as reflected by a maximum twist action of 295lb ft which is available from 1200rpm all the way to 5000rpm. The V6 fitted to the E400 is at its punchiest between 1400 and 4000rpm, where 354lb ft make stability control work overtime. But numbers tell us only so much…
We’re in Portugal, and day one of our big test is devoted to driving on a long coastal road, which takes us north and then curls inland to eventually come round again to the Eastern outskirts of Lisbon. This is Audi country: sun-dried Tarmac dusted with beige sand, no EU money to repair decades of damage done to the pock-marked surface, one corner leading to the next, and more roadside crosses than windswept chevrons. The S5 cannot wait to face these g-force challenges. Thanks to Quattro, putting the power down is limited only by tyre grip. Thanks to the switchable sports suspension, roll, yaw and pitch are kept safely in check.
Thanks to the dual-clutch S-tronic transmission, the engine is firing one torque salvo after another through the close-ratio ’box. Pity that the Dynamic Steering is a little passive even in Dynamic mode, combining lightness and lifelessness while scrubbing off excessive momentum. Although sticking the gearlever in ‘S’ and letting the chips do the work would also put the S5 in express mode, it is so much more rewarding to set the rhythm and pace via the metal shift paddles. The brakes decelerate with aplomb, but tyre grip is again an issue, and we would prefer more feedback through the pedal. The cornering attitude is of the I-go-where-you-point-me kind – at least until you begin to run out of road, lift off, and wait for the Audi to recover in one big gracious arc.
How does the BMW fare in this tricky terrain? It briefly struggles for grip, shaking off the ruffling revs by summoning second, then third gear. Moments later, it enters the zone. The 435i is the lightest car in this group by a 125-150kg margin, but on the N92 the silver coupe feels about 300kg less heavy than the competition. This could be due to the slightly quicker steering, the more eager gearing, the sharper chassis or the beefier low-end punch of the straight-six engine.
Whatever the reasons, the result is more involving and more entertaining handling. But the advantage over E400 and S5 remains surprisingly small, and it virtually pales into insignificance whenever the road opens up and the car moves into triple-digit mph territory. As soon as you touch the brakes again though, this subtle tactility returns, and it connects with your palms as the BMW turns in, aims for the apex and begs for the steering to open up again. For a while, the relatively stiff ride is not a concern anymore. On the approach to the next village, however, where trucks have corrugated the blacktop, stability suffers momentarily and the stopping distance extends by a heartbeat or two. Power is nothing without control? This slogan doesn’t only apply to tyres. It has at least as much to do with the compliance of the suspension.
Same stretch again, this time in the Benz. Switching the dampers to Sport is as straightforward as locking the seven-speed autobox in manual. But to dial in a more lenient ESP setting requires a guide who takes you, via two buttons in the steering-wheel, to the appropriate sub-menu. I did not expect the E400 to shine in this exercise – I could not have been more wrong. True, the Mercedes is not a world champion in the grip and traction sweepstakes. But in ESP Sport, the tail will only wriggle, not swing out of shape altogether. Therefore, it doesn’t take long for confidence to establish itself, and from that moment onwards, the rear-wheel drive coupe (4Matic? Call again in 2017) is an absolute hoot.
For a start, the twin-turbo V6 is arguably the nicest engine we have the pleasure to rate here. It has a bit more muscle where it matters, it does not need to be revved hard to deliver, and it fuses with the transmission in a slo-mo slingshot manner. Oh yes, the body rolls, it dives under hard braking, it squats whenever you tickle the ESP solenoids in a low gear, and you can almost always sense that Mercedes used plenty of rubber when designing the chassis mounts. But the motions are fluent even at ten-tenths, the dialogue between steering and throttle is totally intuitive, and the ride borders on feeling cushy.
Day number two is spent on the Estoril race track, which used to accommodate F1 but is really better suited to motorcycle events. What does one gain by testing a road car on a circuit, you ask? Well, it really is the only place where you can safely explore a vehicle’s limit, perhaps even look beyond it. The Audi should love track days because it is tuned for maximum performance, ultra-fast cornering and neutral handling. But is the S5 really at home on this demanding roller-coaster loop? To find out, we select the sharpest configuration the modular DNA permits and enjoy the amazing straightline urge, the superfast upshifts accompanied by prompt acoustic receipts, and the talented brakes. Through corners slow or fast, however, determined understeer is the name of the game. One could, of course, ignore all warnings and keep the hoof planted, but it helps to bear in mind that the S5 needs considerable acreage to reel itself back in. Again, poor tyre grip spoils the game before it even begins.
Encouraged by its strong on-road performance, we are looking forward to trying the E400 in Estoril. It might be the slowest entrant, but it rarely fails to put a smile on the driver’s face. Especially through the two uphill corners where torque matters more than guts and momentum, the Mercedes lays on the longest drifts. Direction changes are admittedly more ‘Flying Dutchman’ brisk than ‘Hobie Cat’ relaxed, and even if you’re lapping only fractionally faster than your granny, that inertia seat belt will try to strangle you in the first bend you come to. But one hour on the track is plenty to prove that the E-class coupe is not a poseur. Instead, this is a GT with sports car talents which only wait to be unleashed. At the same time, we experience a smooth-riding, waltz-friendly four-seater with zero breakdance ambition.
Why does almost every BMW launch include a track session? Because these cars shine even when you don your gloves, put on the helmet and lower the visor. The 435i matches this picture and meets our expectations, even though it would further benefit from the beefier 335bhp engine installed in the Z4 35is, if only as the ultimate justification of that 4-series moniker. Once more, the BMW feels lighter, nimbler, more agile and quicker overall than the other two contestants. It’s also more chuckable, more willing to assume emphatic cornering attitudes, and more forgiving should your mind be more ambitious than your body is capable. Despite the wider 19in tyres, the silver coupe makes enough beautiful noises to generate a queue of spectators on a nearby flyover.
Having said that, the transition from carving to sliding is less seamless than professed by the Mercedes, second gear is a tad too short even for slow corners, and on the track one does have occasional fond flashbacks to the whiplash seven-speed DKG which expired together with the 335i coupe.
Of course, while the driver experience is always crucial, the finer margins of success tend to be governed by your choice of model and how you spec it. The 4-series range stretches from the 181bhp 420i/420d over the 241bhp 428i and the 254bhp 430d to the 435i and the 308bhp 435d xDrive. Four-wheel drive is available for the 420i/420d, the 428i and the 435i. The desirable eight-speed automatic costs extra on all versions bar 430d and 435d.
For the first time, the transmission will in Eco Pro activate a coasting mode under trailing throttle while at the same time tapping the sat-nav system to look ahead for efficiency relevant factors such as climbs, descents and traffic jams. It’s certainly worth spending the extra £200 on the Sport gearbox, which includes the useful quickshift function and also a Sport mode to speed up the throttle response. Adaptive damping implies that the calibration can be tweaked either way, but this is not the case. While Comfort stays as is, Sport may be pushed to Sport Plus. If you like it very firm, it’s perhaps best to save a bundle by specifying the fixed-rate M suspension.
BMW has added a few retrofit goodies to our car. Perhaps sharing our own (unspoken) concern about the 435i’s power credentials in this company, they’ve pulled a dealer-installed 34bhp upgrade out of the hat. Other available upgrades include a limited-slip differential, a free-flow exhaust and a quite aggressive body kit. Factory options worth considering are sport brakes, variable sports steering and of course bigger wheels. While the standard 17-inchers are shod with standard tubeless tyres, the optional 18s and 19s come only with runflat rubber – an idiosyncrasy which saves 2kg (that’s what the mobility set weighs) at the expense of a compromised ride. True, the tyre technology has improved notably over time, but the 435i still doesn’t come close to the E400 in terms of compliance. The S5? Ah, well. That’s a different story altogether.
Audi is at least as good as BMW in making the customer bleed for fractionally superior vehicle dynamics here and there. Case in point is Drive Select which, in the case of our S5, includes the Quattro sport differential, Dynamic Steering, adaptive sports suspension and adaptive cruise control. Although our blue coupe runs on the smallest available 18in rims with modest 245/40 Bridgestone Potenzas all round, it simply isn’t particularly interested in absorbing obstacles. Instead, the top priority at speeds above 50mph is the total devotion to grip, traction and roadholding.
Even with the electronically controlled dampers set in Sport, the E400 feels a thousand eiderdowns more cosseting than the Audi, and it also beat the BMW by four pillows to one. The fire-red Benz boasts AMG wheels shod with 235/40R 18 Conti SportContacts in the front and 255/35 R18 tyres in the rear. In the course of the recent facelift, MB introduced a new speed-sensitive variable-rate electro-mechanical steering which works rather well. Out of the zillion driver assistance systems fitted to all three candidates, only two stand out: the camera-based 360deg surround view feature offered by BMW and Mercedes, and the automatic cruise control with brake intervention which should really be mandatory in this price class.
So, who wins? The Audi costs most, yet at the end of day two it is the least loved of the three cars. It still looks stunning, its interior still feels special, and it’s still the coupe to beat against the stopwatch in a straight line. But it tells you plenty about this segment of the market that those qualities aren’t enough to win. So, BMW or Mercedes? If we were talking convertibles here, I would jump at the E400, simply because the 4-series cabrio will adopt the ungainly retractable hardtop from the outgoing 3-series. The Benz has a lot of other things going for it, too. Perceived quality, for instance, style at least from certain angles, packaging (biggest boot, most rear legroom), a great engine and that magic carpet ride. On the debit side, ho-hum ergonomics, a rather steep asking price, the absence of four-wheel drive and not much else. Sure, the neatly balanced and admirably competent 435i is even more fun to drive. But in the mirror of the BMW, the E-class looms larger than expected.
Having said that, the BMW is more affordable, and although it doesn’t look quite special enough inside and out to justify that trumpeted 4-series badge, number four-three-five is again the pacesetter when it comes to having fun from A to B. And back. And forth again.