Audi A4 vs A3 Saloon: sibling showdown

The arrival of the new Audi A4 marks one of the most important car launches of the year. The latest four-door compact executive will have to be seriously talented if it is to compete with the BMW 3 Series, Mercedes C-Class and Jaguar XE.

Before it takes them on, however, it also has a rival much closer to home. The A4’s baby brother, the A3, is available in saloon form, too. So is the latest A4 set to justify its extra asking price over the smaller car?

Styling

We could perhaps summarise this section with one short statement: if you like the look of the Audi A3 saloon, you’ll like the look of the A4, too.

From a distance, it seems little has changed from the old car and, indeed, the design of the A3 saloon. The “serrated” lower edges of the A4’s headlights give its face a look familiar to TT owners, while the lower air intakes mirror their shape. A large hexagonal grille dominates the front just like every other Audi on sale.

Along the sides, both feature similar sharp creases, a sloping roofline and squared-off boot design. Only the length sets them apart – the A3 measures 4,456mm, while the A4 is 270mm longer.

The story is much the same at the rear – aside from a distinctive light signature from the LED taillights, you’d be hard pushed to tell the difference between the two until you moved close enough to read the badges.

Interior

The A3’s cabin is definitely one of its selling points. The dashboard is simple and modern, with two central air vents that sit above the heating controls, while most of the infotainment functions can be tweaked through Audi’s MMI system.

The A4’s dash is slightly angled towards the driver for a sportier feel, although the infotainment screen – like many recent Mercedes models – appears to sit on top of the dash. The central console is wide, helping to contribute to impressive shoulder room for front seat passengers. Ahead of the driver, the fantastic LCD instrument panel found in both the TT and the Lamborghini Huracan is optionally available in place of traditional dials.

For the fifth generation A4, Audi’s MMI interface has been completely redesigned. Audi says the menu system is designed to more closely mimic smartphones which, in theory, should make the system more intuitive to use than the one found in the A3.

If you frequently carry taller passengers, the A4 is the one to go for. Already larger than the A3 in its previous guise, the new model offers 11 and 24mm more legroom front and rear than the old car. The A3 shares its platform with the likes of the Volkswagen Golf, and therefore cabin space should be more than adequate for most families, even if it can’t match the A4.

Driving

While the exterior styling suggests not much has changed from the old A4, under the skin almost everything is new – or at least extensively updated. The A4 sits on an entirely new platform set to underpin Audi and VW’s biggest cars in the future. Thanks to the increased use of lightweight materials – including an aluminium roof to lower the centre of gravity – the A4 is now 120kg lighter than before. At 1,320kg, the lightest A4 is now just 80kg heavier than an equivalent A3 saloon.

Both cars send their power to the front wheels, with the option of four-wheel drive further up the ranges. Audi claims the A4 is one of the most refined cars in its class, thanks to a rigid body structure, fancy door seals and acoustic glass. While the A3 boasts impressive refinement itself, the A4 should have it covered in this area.

Engines

The A4 is set to hit showrooms with a choice of three petrol and four diesel engines. Being the larger car of the pair, the A4 is available with the more powerful engine choices than the A3, particularly when it comes to diesels.

Two versions of the current 2.0-litre diesel are offered, albeit upgraded to pass the most stringent EU emissions regulations. With either 150 or 184hp on tap, these units produce the same power as those offered in the A3. However, an eco-minded Ultra version is claimed to return 76.4mpg – a full 7.5mpg better than the A3 can achieve. The A4 benefits from a powerful 3.0-litre V6 diesel – despite producing as much as 275hp, mpg figures in the mid-sixties are still expected.

The A4’s entry-level petrol is a 150hp 1.4-litre turbocharged unit. It’s also available in a largely similar guise in the A3 but, due to the lower weight, is slightly faster in the smaller car. 2.0-litre turbo petrols are offered higher up the A4 range, while the A3 makes use of a smaller, more frugal 1.2-litre turbo at lower price points.

The A4’s new six-speed manual gearbox saves 16kg over the old unit which can be found in the A3. An updated eight-speed automatic can be paired with the A4’s V6 diesel, which includes a coasting function to improve fuel economy.

Value for money

Audi has yet to disclose prices for the new A4, but the outgoing car cost approximately £3-4,000 more than the equivalent A3 saloon. For that price, buyers benefit from the greater cabin space, the option of more powerful engines, and the latest safety tech.

Thanks to the improvements in aerodynamics and reduction in weight, the A4 is unlikely to be significantly more expensive to run on a day-to-day basis than the A3 and, as mentioned previously, it could end up even cheaper.

Verdict

The A4 represents all the latest know-how from Audi crammed into one car. On paper, it looks set to be one of the most competitive models in its class, and we’d say, overall, it’s more than likely to offer a superior drive to that found in the A3.

However, the A3 Saloon still has many merits. If performance isn’t a priority, plump for the 1.2-litre petrol and save thousands of pounds off the A4’s asking price. The two cars look so similar, the average passer-by will hardly notice. It still boasts a gorgeous cabin anyway, and it’s more than practical enough for most.

In other words, if your finances allow, we’d suggest placing a deposit on the A4, but if not, then the A3 will be more than up to the task.