Accounting for half of all the vehicles Audi makes, the A4 is Ingolstadt's bread and butter, so failure is not an option. The competition is tough, though, principally from the BMW 3-Series and Mercedes C-Class. Sharing the svelte lines of the A5 coupe, the new A4 is handsome and smart, if not visually groundbreaking. Helping it stand out from the crowd on the road are the daytime running lights that, until now, were the preserve of high-performance Audis. Not only does the A4 borrow its looks from the A5, it nabs its underpinnings too, including a front axle that's further forward than the old A4's, for better weight distribution. It comes with Audi Drive Select, which, at the touch of a button, varies the suspension's damping, shift speed on autos and steering ratio for a more sporting or more comfortable drive. There will be 10 engines, starting with 120bhp and 158bhp versions of the 1.8-litre turbo petrol and two versions of the Golf GTI's 2.0 TFSI engine with 178 or 208bhp. Topping the petrol range is a muscular 261bhp 3.2 V6, until sportier S4 and RS4 versions arrive later. Top of the diesel range is a revised 237bhp 3.0 V6 that initially will be manual only. Sitting just below will be another V6 diesel, the smaller 187bhp 2.7 that's mated to Audi's smooth Multitronic CVT automatic.