Alfa Romeo 159 1750 TBi

What is it?

It’s Alfa’s new high-tech, down-sized petrol engine, which spearheads a challenge to get the 159 back on track as a genuine mid-sized sports saloon.

There has also been plenty of work done to lift the 159 from its dynamic mediocrity into the sort of machine that more fulfils the adventure promised by its looks.

The engine has had the legendary twin-spark head removed altogether in favour of modern direct-injection, while around 70kg has been stripped out of the architecture and the steering’s been tweaked for more feedback.

What’s it like?

Now sporting 197bhp out of the so-called 1750 four-cylinder turbo petrol engine (it’s actually a 1742cc engine, but they like the history of 1750), it’s a cleaner, crisper, sharper engine and, as a bonus, it’s faster, too.

Yet there’s more than meets the eye, because this is the latest in the trend to downsize engines for economy while maintaining outputs, so when Alfa’s literature says it’s 100kg lighter, they actually mean that the saloon’s 1430kg is 100kg lighter than a similarly-powered V6…

It doesn’t sound that much different when you fire it up, but it’s smoother in its feel and the few vibrations it has a charmingly warm, rather than tiring or annoying or distracting.

In six-speed manual form it has become a very flexible mid-sizer. The new cylinder head, with seven-hole, direct-fuel injection and much-improved scavenging, has 70 per cent more torque at 1500rpm than the old engine did and that makes it nearly stall proof.

Much like Audi’s turbo petrol power plants, Alfa seems to have gone out of its way to give the engine a diesel-esque feel at low rpm while trying to maintain the flinging feel of a petrol engine up high. While tuning the turbo helps, it’s also got variable inlet and exhaust timing and the frictional losses from its new roller rocker arms have reduced frictional losses at 2000rpm by 65 per cent over the twin-spark.

Not only does it thump out a V6-like 236lb ft of torque at just 2000rpm, but the power peak doesn’t just come and go. Instead, it holds its torque peak for an eternity before the power takes over at 4750, then remain in charge all the way to 5500rpm.

And that’s how it feels on the road, too. It sounds and feels strong and unburstable, it’s willing and flexible in any gear, and it really only sacrifices the elasticity of the last 500 revs to do it.

It sprints to 62mph in 7.7 seconds, but the 159 still feels like a hefty piece of gear. It’s much better on the move, once the inertia has been overcome, pulling willingly to a 146mph top speed.

It’s had a suspension fiddle as well and its direction changes have benefitted significantly from the diet. Ride quality on UK roads has become something of a thorny issue with Alfa, so while we’ll confirm that the car rode with comfort and security in Balocco, we’ll reserve final judgement until it turns up over here.

After all, it might have been retuned, but it still sits on the original 159 hardware, so that means 17-inch rubber, a multi-link rear and double wishbones up front.