There has been no major revolution in the engine line-up, but the range benefits from subtle modifications and improvements so Audi A4 performance has been upgraded slightly.
The entry level engine is the 1.8 TFSI with 120bhp, which is smooth and quiet, while offering good low down pulling power thanks to the fact it's turbocharged. This engine is also available with 160bhp which brings the 0-62mph down from 10.5 seconds to 8.6 seconds and is also available with an automatic gearbox. But for even quicker performance, there's the superb 2.0 TFSI - an engine shared with the 2005 Volkswagen Golf GTI. Thanks to 211bhp it accelerates from 0-62mph in just 6.9 seconds and is available with an eight-speed Multitronic gearbox which uses two clutches to deliver super-fast shifts. The 3.2-litre V6 uses Audi's FSI fuel-saving direct injection technology and with 265bhp (increased from 255bhp on the previous A4), it's a lively performer reaching 62mph in 6.2 seconds, with a top speed electronically limited to 155mph.
The popular 2.0 TDI has changed significantly thanks to the adoption of 'common rail' technology and this has resulted in a huge improvement in refinement and noise levels. It's available in several power outputs - 120bhp, 143bhp and 170bhp - and all offer strong in-gear performance along with impressive economy. In October 2009 a 2.0 TDIe model was introduced which uses a stop/start system, low rolling resistance tyres and aerodynamic tweaks to average 61mpg while emissions are just 120g/km of CO2, making it cheap to tax. It doesn't feel slow though and the 136bhp engine will accelerate from 0-62mph in 9.5 seconds - almost identical to the 143bhp 2.0 TDI. Audi's six-cylinder diesel engines - both the 2.7 TDI and 3.0 TDI are improved for 2008. The 2.7 TDI (available in front-wheel drive only) gets an extra 10bhp over the previous version (now 190bhp) and with its Multitronic automatic transmission it will sprint from 0-62mph in 7.7 seconds. The 3.0 TDI quattro has many new components and is quicker in the dash from 0-62mph than the 3.2-litre petrol engine plus thanks to huge pulling power it makes an excellent long distance cruiser. Impressively it accelerates from 0-62mph in a mere 6.1 seconds - quicker than most hot hatches.
In 2014 the 2-litre TDI Ultra engine was introduced to the A4 saloon range, building on the efficiency for the previous 2.0 TDIe.
This completely new 161bhp unit has improved torque, from 380Nm to 400Nm and is marginally quicker from 0-62mph, which is reached in 8.3 seconds. Audi claim the Ultra engine will produce 109g/km of CO2 and reach 67.3mpg on a combined cycle.
Equipped with an Ultra engine, the A4 Saloon is in road tax band B, with benefit-in-kind liabilities of 16 percent.
One of the criticisms of the previous A4 was that it wasn't particularly engaging to drive. Audi has certainly taken that on board and worked to make this version more enjoyable. It has superb body control, feels surefooted in corners and has sharp steering with a positive turn-in. Audi is also offering a selection of electronic aids to make the driving experience more engaging - one example is Audi Drive Select which can alter settings for the engine, steering, automatic gearbox and suspension.
However even without these extra systems the A4 has a more intuitive feel than before and a composed ride, dealing with bumps on the road surface with ease.