Mercedes C-Class vs Audi A4 – which is best?

Why? Because carmakers are now obsessed with SUVs, which have a noticeable price hike over their saloon counterparts. A used C-Class, for example – a practical, four-seater car – costs several thousand pounds less than an equivalent Mercedes GLC SUV, which only has a bit more passenger space. This is also true when comparing the A4 to the Audi Q5.

So, savvy shoppers, which of these posh – but surprisingly affordable – saloons is the best pick? 

Mercedes C-Class vs Audi A4 compared

Styling and design

Mercedes C-Class (left) vs Audi A4 (right)

Mercedes and Audi made their names with models like the C-Class and A4, and both cars remain showcases for their brands' styling languages. Mercedes' latest look is swoopy, with exaggerated curves on the headlights, front grille and side windows. It's clean and handsome but steers clear of any more dramatic styling that might risk dividing opinion, so isn't the best choice if you want to stand out from the crowd.

Similarly, the A4 has a fairly conservative design. You'll find the familiar Audi family face with a bluff hexagonal grille and angular headlights, but no left-field choices either. Audi's styling relies more on straight lines than the Mercedes and your personal taste will be the guide for which you prefer.

Both models are also available as five-door estates. These get longer roofs to cover their larger cargo areas and hatchback-style boot lids for better access.

Interior and practicality

Mercedes C-Class (left) vs Audi A4 (right)

Take a seat in the C-Class and it's obvious this car is one generation ahead of the A4, with an all-new Mercedes model arriving in 2021. There's lots of modern-looking ambient lighting and absolutely massive screens for the infotainment system and driver's dials. You'll find lots of luxurious leather and metal details throughout the cabin, too, helping the C-Class feel a cut above its main rivals – even though the gap is far from night and day.

There are some annoying shortcomings in the C-Class, however. Too much control has been ceded to the screens, including the all-important climate controls – and the touch-sensitive buttons that remain on the dashboard and steering wheel for stereo volume and drive mode are fiddly to use. Mercedes has also bestowed the C-Class with a big slab of grey plastic across the lower dash on all but range-topping models, which feels surprisingly cheap when looked at in isolation.

While the A4 doesn't feel as modern as the C-Class, that's not necessarily a bad thing. It has proper physical controls for the climate and stereo functions, which are easy to adjust with barely a glance versus the Mercedes' frustrating touch-based setup. The infotainment graphics, too, are less fussy than the C-Class, making the system easier to navigate. Material and build quality are generally excellent, so the A4 feels like a premium product.

Passenger space is comparable between both cars. Differences will come down to a few millimetres here or there, with both cars able to seat four tall adults comfortably – or five for shorter journeys. The Audi has a few extra litres of boot space and a marginally larger opening if you're comparing saloon models, but estate versions are even closer, making either a great option if you need room for a pushchair or a pooch.

Engines and performance

Mercedes C-Class (left) vs Audi A4 (right)

The C-Class's entry-level engines are noticeably more powerful than those offered on the A4, although Audi has competitive units higher up in the lineup. If you're an average motorist covering a mix of short and long journeys, you might appreciate the relative affordability of these cars' petrol engines, but you should only pick the A4's 35 TFSI engine if you're not bothered about performance. At normal speeds, the engine works fine but it can't match the grunty acceleration of the more powerful engine options when you put your foot down.

Diesel engines are popular on both models, with lots of low-down muscle when accelerating and strong long-range economy. Again, the A4's 35 TDI engine undercuts the Mercedes on both power and price but still feels like a good match for the Audi, so is easy to recommend. Just be mindful that diesels need the occasional longer journey to avoid DPF issues.

All C-Classes are automatic only now, but you'll still find quite a few A4s with manual gearboxes. Audi's manual shifter is a pleasure to use, with an easy, positive action, but we'd still pick an auto if pressed because we think it suits the car's effortless persona better. Progressively more power is available higher up both cars' ranges, including the spicy Mercedes C43 AMG and Audi S4, or the positively frightening C63 S and RS4 – all have far more performance than any sensible person would need on the road, making them a hoot to drive.

Driving

Mercedes C-Class (left) vs Audi A4 (right)

Behind the wheel, you'd need to be something of a connoisseur to tell many meaningful differences between the two cars. They both feel generally safe and predictable, with a fine balance between handling and ride comfort – neither feeling too sporty, or too soft and wobbly, either.

The C-Class feels, to us, like it's set up a fraction more comfortable than the Audi, with a touch more absorption over big bumps, and a little more sway to its body motions as it cancels those bumps out. That translates to a slightly softer response at the wheel through corners as the C-Class's weight leans over to the outside edge but, again, you simply won't notice or appreciate these fine differences while driving in the real world.

To that end, the Audi is actually the slightly more engaging car to drive. It has keener responses as you drive more aggressively and seemingly endless grip, whether you choose a standard two-wheel-drive version or one with optional quattro all-wheel drive. It is a spot firmer than the C-Class but still has plenty of compliance to deal with potholes and speed bumps.

Value and reliability 

Mercedes C-Class (left) vs Audi A4 (right)

The value-for-money argument for both the C-Class and A4 has already been won. These cars have similar levels of practicality as modern SUVs – especially in estate form – but cost thousands of pounds less to buy. That makes them a cost-effective route into premium-car ownership.

Compared to each other, prices are remarkably close on the used market. Age, spec and mileage will play a much larger role in determining which car is more affordable, rather than the badge on the bonnet. That means you can freely choose the car you prefer, without stressing over which model will save you a few extra pounds here or there.

Both brands score mid-table results in reliability surveys. Respondents rarely flag up serious mechanical problems but both cars come loaded with lots on-board equipment, which means more potential points of failure further down the line compared to simpler, more affordable models. You can offset any concerns by buying an extended warranty with either car, to protect you from the cost of unexpected repairs.

Which is best?

Mercedes C-Class (left) vs Audi A4 (right)

These cars are close competitors – so close that the differences between them aren't great enough that you can pick a clear winner. The Mercedes is a touch more luxurious and comfortable, but the Audi is a fraction better to drive with better everyday usability.

Either way, the desirable badge on the bonnet and the relative clamour over SUVs means these saloons are a smart way to put a posh car on your drive. You don't pay a premium for a faux off-roader and their slow depreciation means monthly PCP costs are competitive.

Find out how much you could save by buying or financing a used Mercedes C-Class or used Audi A4 from Motorpoint. For more info, read our in-depth Mercedes C-Class review or our Audi A4 review.