Here is an excerpt from the comprehensive review:
“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…
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?
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.