There were originally are three petrol engines available starting with the 140bhp 1.8-litre MPI. A 1.9-litre engine was offered at launch but was soon replaced by the 1.8. The 2.2-litre JTS boosts power to 185bhp and pulls strongly from low revs but if Alfa 159 performance is a priority go for the range-topping model powered by a 3.2-litre V6 with a hefty 260bhp.
It's the diesels which are really the strong point of the 159 line-up however with both the 1.9-litre and 2.4-litre JTDM units superb performers. With 150bhp the smaller engine offers a great blend of punchy performance and economy while the larger five-cylinder 2.4-litre unit initially came with 200bhp, with an uprated 210bhp version launched in September 2007.
In August 2009 an ECO model was introduced that uses the 1.9 JTDM engine but with power lowered to 120bhp. As a result economy improves from 50mpg to 54mpg. In the same month two more engines were added including the superb 1750 TBi turbocharged petrol with 200bhp. It's not the most characterful sounding engine around, but it's incredibly smooth and strong, with effortless in-gear acceleration, making it great for overtaking.
Thanks to the turbo it has plenty of low down pulling power, although there can a slight lag when driving quickly and fast gearchanges under hard acceleration can result in a brief pause as you wait for the turbo to kick in. But this is only a minor criticism and in everyday driving it's enjoyable to drive with a 0-62mph time of 7.7 seconds while economy is an acceptable 35mpg.
The other engine is the 2.0 JTDM diesel with 170bhp that covers the 0-62mph sprint in 8.8 seconds - less than a second slower than the more powerful 2.4 JTDM, yet economy is an impressive 52mpg. With the exception of the five-speed 1.8-litre model, all models have a smooth six-speed gearbox. A six-speed auto (known as QTRONIC and not to be confused with Q4, the four-wheel drive system) is available on the V6 and the diesel engines.
Alfa has managed to strike a pretty good balance between sporty body-control and comfort, with the most versions of the 159 treating occupants to an impressively refined ride. However, sporty TI models come with larger (19-inch) alloy wheels and lowered sports suspension, but while they look good, the ride is very firm and not pleasant over rough or bumpy roads.
But like the rest of the range, they handle well thanks to responsive and well-weighted steering. Most models are front-wheel drive, but the 3.2-litre V6 and 2.4-litre JTD models are also available as Q4 versions. This signifies that it uses Alfa's four-wheel drive system, offering more traction. An electronic stability control system helps keep things tidy in slippery conditions.