As with the saloon, the Avant featured no less than 14 engine choices during it's lifespan. The 1.6-litre petrol is the smallest and is underpowered so the better bets are the turbocharged 1.8T and 2.0T units or the efficient 2.0 FSI. There's also a 200bhp 2.0 TFSI - an engine shared with the Golf GTI which gives the A4 a 0-62mph time of 7.3 seconds (a special edition version with 220bhp was available for a short time in 2006).
The only petrol V6 is the smooth 3.2-litre FSI unit with 256bhp or there's the 4.2-litre V8 in the S4. The diesel line-up is just as impressive - the most frugal is the 1.9TDI with 115bhp but if you want a bit more performance the 2.0 TDI with 140bhp provides sufficient power (later a 170bhp variant was introduced). Elsewhere there's a 2.5 V6 TDI (replaced in 2006 by a more refined 2.7 TDI unit with 180bhp) or a 3.0 V6 TDI with 204bhp and 450Nm of pulling power.
There's a choice of five and six-speed gearboxes, plus a six-speed automatic and a seven-speed CVT. The superb 420bhp RS4 quattro powered by a 4.2-litre V8 is the ultimate for performance and is covered in a separate review.
The A4 continues to differ from the BMW 3-Series and Mercedes C-Class by being front-wheel-driven or with the option of quattro all-wheel-drive on more powerful versions. Even so the handling is safe and predictable, while the quattro equipped models are exceptionally sure footed. A new steering system goes some way to addressing previous criticisms of unresponsive steering, although it still not quite as good as the BMW.