BMW 3 Series vs Audi A4: used car comparison

21 March 2022
Updated: 8 July 2022

While SUVs have become the family car of choice, the BMW 3 Series and Audi A4 saloons are still very popular. They combine a spacious, family-size interior with the comfort and sophistication of a luxury car you’d expect to pay more for.

But which is best? Here’s our guide to the 3 Series vs the A4, looking at how they compare in key areas. We’re looking at the latest models –the 3 Series sold new from 2018 and the A4 sold new from 2016.

The 3 Series and A4 come well-stocked with high-tech features. All versions of both cars have an infotainment system featuring sat nav, Bluetooth and smartphone connectivity, plus lots of other features. Be aware that some earlier 3 Series and A4 models have either Apple CarPlay or Android Auto compatibility. It’s only in the past couple of years that they’ve had both.

The cars also have climate control, cruise control, parking sensors and a digital driver’s display. Higher-spec models have additional features such as heated leather seats.

Higher-spec 3 Series and A4 cars come with extra infotainment features including the ability to sync your phone to the sat nav to automatically set a route to your next destination. BMW and Audi also have smartphone apps that can show information about the car, and control certain features.

The 3 Series has an attractive, user-friendly interior but the A4’s feels even more beautifully crafted, which gives it a bigger wow factor.

Both the 3 Series and the A4 have a lot of space in the front seats whatever size you are, though the BMW has a higher console between the seats which can make it feel less spacious than it actually is. In the back, there’s not much difference between them. Two tall people fit comfortably and a third can squeeze into the middle back seat for shorter journeys. If you have two children, either car will have all the space you need.

Each car has exactly the same amount of boot space – 480 litres, which is enough for a few big suitcases when you go on holiday. The BMW’s boot has a bigger opening and a squarer shape, so it’s easier to load. Both cars’ back seats fold down for carrying longer loads

If you need to carry even more, the 3 Series and the A4 are available as estate models: the 3 Series Touring and Audi A4 Avant. The Touring has a marginally bigger boot than the Avant with the back seats in place (500 litres vs 495 litres), but space is identical with them folded down (1,510 litres). The Touring’s back window lifts up without opening the entire boot lid, so you can load small items more easily.

If you prefer a slightly higher seating position, the Audi A4 Allroad is worth considering. It’s an A4 Avant with additional SUV-style design details and a higher ride height.

• What is a saloon car?

• Best used saloon cars

• BMW SUV models – a buyer's guide

The 3 Series and the A4 are both great to drive, but, in different ways. When you’re just going from Point A to Point B they’re quiet, comfortable and hassle-free to park. It’s out on the open road that the differences become clearer.

The A4 feels more relaxed, letting you luxuriate in its beautifully made interior and very comfy seats. It’s great for long journeys, taking the stress and strain out of a motorway slog. So does the 3 Series, but it feels much more agile and engaging – fun, in other words – on country roads.

Both cars are available with a wide range of petrol and diesel engines. Even the least powerful models give smooth, responsive acceleration; the higher-powerful versions of each are seriously fast. Manual gearboxes are available, but most buyers go for an automatic, which is standard on the more powerful models anyway. You can also get four-wheel drive, branded ‘xDRIVE’ on the BMW and ‘quattro’ on the Audi.

BMW and Audi are premium brands so their cars cost more than ‘mainstream’ brands like Ford. But the quality of the 3 Series and the A4 and the wealth of standard features make them both decent value and all but the most sporty versions are very fuel-efficient.

The A4 has the edge, though. According to official average figures, A4s with ‘TFSi’ petrol engines can give fuel economy of 36-46mpg and ‘TDi’ diesels can give 49-60mpg. The 3 Series can give 41-43mpg with an ‘i’ petrol engine and 47-55mpg with a ‘d’ diesel.

Only the 3 Series is available as a plug-in hybrid. The petrol-electric 330e has a zero-emissions range of up to 41 miles and takes less than four hours to fully recharge from a home EV charger. Some newer 3 Series and A4 models have mild-hybrid technology that improves fuel economy and reduces emissions but doesn’t offer electric-only power.

Safety organisation Euro NCAP awarded the 3 Series and A4 its full five-star ratings. Both feature driver safety systems that could help you avoid a collision in the first place. Some of those are standard in the Audi but cost extra in the BMW.

Both cars are built to very high standards, but the A4 feels like it’s put together with an extra degree of precision. Neither Audi nor BMW scored well in the most recent J.D. Power UK Vehicle Dependability Study – Audi was 22nd out of 24 car brands, while BMW ranked bottom of the table.

BMW 3 Series

Length: 4,709mm

Width: 2,068mm (including door mirrors)

Height: 1,435mm

Boot space: 480 litres (saloon); 500 litres (estate)

Audi A4

Length: 4,762mm

Width: 2,022mm (including door mirrors)

Height: 1,428mm

Boot space: 480 litres (saloon) 495 litres (estate)

The BMW 3 Series and Audi A4 are both excellent cars that show you don’t necessarily need an SUV if you have a family. They also feel a sensible size if you don’t regularly carry passengers or fill the boot.

Choosing between them is tough because they’re very closely matched. Taking the cars’ design and brand out of the equation – which may swing your decision – we’re going to give first place to the Audi A4. It’s not as much fun to drive as the BMW but it has the more impressive interior and tech, its petrol and diesel engines are more efficient and it’s that bit better at soothing away the stresses and strains of everyday driving.

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