The oldest cars in Alfa Romeo's current line-up, the 147 hatchback and GT coupé, have received some fettling to bring the driving experience bang up-to-date. An increasingly common problem as modern turbodiesels get ever more powerful and refined is smoothly channelling the large lumps of torque they produce through the front wheels. Alfa has attempted to address this by offering as an option on its 1.9-litre JTDm models a torsen (torque sensing) differential to transfer power between the front wheels when it detects one starting to spin and given these cars the Q2 moniker.

The 147is Alfa's offering in the premium hatchback class, rivalling the VW Golf and Audi A3, is available in three and five door flavours, and although it is getting rather long in the tooth, a couple of facelifts have kept it looking fresh while undercutting most of its competitors. The GT is another old school Alfa and now, with the presence of the Brera something of an anomaly, but with a substantially lower starting price of around £20,000 which places it in Mazda RX-8 territory. And like the Japanese car it has a set of properly useable rear seats rather than the child-only perches of its newer sister.

That depends on whether you want your driving experience moderated by electronics or more old fashioned, and arguably more satisfying, mechanical means. The Q2 option adds around £1,500 to the price of either the 147 or GT and as well as the trick diff get lowered suspension along with new anti-roll bars, springs and dampers. Externally the cars are marked out by larger alloys, rear spoiler, chromed exhaust and boot badge while inside you will find sports seats (leather in the GT), red dials and stitching, an uprated stereo and wheel mounted controls for the standard ESP, cruise control and the aforementioned sounds. The Q2 system can also be had without the cosmetic tweaks for just £450.

Compare the Alfa GT and the Mazda RX-8 side-by-side

The term 'Q Car' generally refers to a fast motor that trades aggression for discretion and while neither of these Alfas are wallflowers, particularly the still stunning GT, both do improve on their non-Q2 cousins as far as the business of going quickly is concerned. This isn't the first time a limited-slip differential has been placed between the front wheels of a car and while it does undoubtedly improve cornering speeds it can make the car feel slightly nervous as the grip is transferred side-to-side. Thanks to its sophisticated double wishbone suspension however, neither car suffers from this in the same way as, say, the Renaultsport Megane with its cheaper Macpherson strut set-up.

On a track, the 147 was impressively agile, cornering quickly and allowing hard acceleration away from the apex without spinning the power away through the inside wheel. The sensation through the wheel is uncannily like the one we have all experienced as a learner when our steering went slightly wayward and the reassuring hand of a parent or instructor added some input. On streaming wet and very muddy country roads the GT inspired confidence, the increased grip levels allowing greater driver control because it prevented the stability programme having to intervene.

The larger wheels that come as part of the Q2 package - 17-inch on the 147 and 18-inch on the GT - not surprisingly have a detrimental affect on the ride. The latter in particular never feels entirely settled on the motorway and also suffers from a degree of wind noise from its frameless windows, enough to have me wondering a couple of times if it was properly closed. And while the diesel is pleasingly throaty when extended, it can't touch German rivals for refinement. Both cars also betray their age when it comes to interior accommodation; rear legroom is tight in the 147 and both suffer somewhat from the traditional Italian position that is best suited to those with long arms and short legs.

Compare the 147 and the VW Golf side-by-side

Driving position aside, Alfa is rather good at stylish cabins which, while not always the best screwed together, do impart a sense of occasion from the driver's seat. These two might lack the machined aluminium of the 159, Brera and Spider but steel grey trim imparts a sporty touch as do the deeply recessed dials and good-to-grasp leather bound three-spoke steering wheel. Controls are well weighted, the clutch light and the gearbox has short, if slightly notchy, throw. Swift steering with few turns lock-to-lock may be a boon on the open road but does translate into a slightly larger turning circle so neither car is the neatest parker.

Both cars use identical four-cylinder 1.9-litre turbodiesels producing 148bhp and 225lb/ft of torque. Performance wise this translates into 0-62mph in 8.8 seconds and a top speed of 129mph in the 147 while the heavier but obviously more slippery GT sprints to 62mph in 9.6 seconds but hits 130mph. At the pumps, the 147 drinks diesel at a rate of 35.3mpg, converting it into 157g of carbon dioxide every kilometre. Figures for the GT are 33.2mpg and 165g/km. Neither car is hugely impressive in this respect when the faster BMW 120d coupé returns nearer 60mpg and a VW Golf TDI GT more than 50mpg.

Compare the Alfa GT and the BMW 1-Series side-by-side