Mercedes C-Class vs BMW 3 Series: Which Should You Buy?

The Mercedes C-Class and BMW 3 Series are two of the most popular Saloon cars in the UK. For buyers seeking a practical yet sporty saloon, both make compelling choices, but, how do you decide between the two? 

 
We thought we’d compare the C-Class and 3 Series across different categories to help you pick the best option.

Engine Performance and Fuel Efficiency

 
The Mercedes C-Class and BMW 3 Series are closely matched when it comes to engine performance. 

Mercedes offers a range of four-cylinder petrol and diesel engines producing between 154-258 horsepower. There is also a powerful 3.0L inline six-cylinder with 362 hp. 

 
BMW provides similar engine options with four-cylinder units outputting between 184-255 horsepower. Their six-cylinder tops out at 382 hp. Both brands employ 48-volt mild hybrid systems for improved efficiency. 

 
In real-world driving the engines feel evenly paired - the four-cylinder C-Class and 3 Series models have comparable acceleration and responsiveness. Fuel economy is also very similar across engines of equal size. The six-cylinder models provide an extra dash of power and refinement. 

Ultimately both the C-Class and 3 Series offer a range of strong petrol and diesel engines suited to different budgets and needs. Drivers will be happy with the performance of either premium compact saloon.

Winner: Draw

Performance and Handling

 
The 3 Series delivers exceptional sharpness, responsive steering and minimal body roll around corners. It reacts quickly to the drivers' input with agile precision through curves. The balanced rear-wheel drive chassis and limited slip differential enable expertly controlled power delivery.  

Whilst no slouch, the C-Class exhibits more understeer in corners and feels less eager to change direction. The steering conveys stability but lacks the intimate connection to the road you get in a 3 Series. If you enjoy having fun on the road, the 3 Series gives you that fun.

 
While the C-Class provides a compliant, comfortable ride, the 3 Series offers the purest driving enjoyment for enthusiasts who relish carving twisty roads. When it comes to driving dynamics, the BMW 3 Series is still the handling champion over the Mercedes C-Class. 

 
Winner: BMW 3 Series

Interior Design and Technology

 
It’s fair to say both cars have incredible interiors. Both excel with upscale cabins featuring premium materials and contemporary tech.

 
The C-Class goes for elegance with open-pore wood and quilted leather, while the 3 Series focuses on driver-centric design. The BMW also introduces the latest iDrive infotainment system with digital gauges. Its overall interior ambience nudges slightly ahead of the Mercedes. 

 
However, the C-Class wins points for rear seat roominess. Both models offer high-tech interiors with digital instrument panels and large centre touchscreens, which all drivers now expect from all vehicles. The C-Class impresses with its ‘Hyperscreen’ on the latest models - a continuous curved display spanning the entire dashboard. The 3 Series counters with BMW's latest iDrive 8 infotainment. It’s safe to say you get leading-edge tech in both cars.

 
Winner: Draw

Styling

The C-Class adopts Mercedes’ “sensual purity” design language with a flowing, curvaceous shape and relaxed forms. The front sports a large grille and sleek LED headlamps. The side profile conveys elegance with a swooping character line. Full-width rear lights emphasize width. The interior matches the exterior with upscale, flowing designs. 

In contrast, the 3 Series features a more aggressive styling. The bigger grille, angular headlights and chiselled bumpers provide a cutting-edge sporty look. The side view appears poised to pounce with taught lines and muscular flared wheel arches. BMW’s interior feels focused on the driver. 

 
If you’re thinking between these two models you will likely be swayed by whether you prefer the graceful, luxurious aesthetic of the C-Class or the athletic, sporty styling of the 3 Series. Both exude a contemporary style. Styling preference will come down to individual taste, but the 3 Series gets a small nod for its athletic, modern design. The C-Class looks elegant but less eye-catching. Mercedes still has an aura of luxury that exceeds BMW's more sporty image in the UK market. 

 
Winner: Draw

Costs and Ownership Value

When it comes to costs and long-term ownership value, the C-Class has a slight edge over the 3 Series in the UK market. 

The Mercedes carries a higher starting price than an equivalent 3 Series. However, the C-Class enjoys better residual values over a typical finance period. Mercedes ranked highest among premium brands for residual value in recent cap hpi research. The C-Class is estimated to retain around 10% more of its value after 3-4 years versus the 3 Series. This means the depreciation gap will narrow when selling or trading in. 

 
Day-to-day running costs are nearly identical between the two models in terms of fuel, insurance, tax and maintenance. While the BMW costs less upfront, the Mercedes' resale value makes it competitive from a total cost of ownership perspective over the full vehicle lifecycle.

 
Winner: Mercedes C-Class

Dimensions

The latest Mercedes C-Class has grown in size compared to its predecessor, making it larger overall than the BMW 3 Series. The current C-Class measures 4751mm long, 1820mm wide, and 1438mm tall with a wheelbase spanning 2865mm. This makes it 89mm longer than the previous generation. 

By comparison, the 3 Series has dimensions of 4713mm long, 1827mm wide, 1442mm tall, and a 2851mm wheelbase. So while the 3 Series is slightly wider, the C-Class surpasses it in length by nearly 40mm. This extra length for the Mercedes translates into more rear seat legroom and a bit more boot space.
With 455 litres of boot space, the C-Class bests the 430 litre capacity in the 3 Series. Buyers who frequently transport passengers or bulky items may appreciate the added practicality offered by the new C-Class based on its larger overall footprint.

 
Winner: Mercedes C-Class

Running Costs

The Mercedes C-Class and BMW 3 Series have very similar running costs. Fuel economy across four-cylinder petrol and diesel engines ranges from 40-50mpg in mixed driving conditions. The six-cylinder models sacrifice economy slightly for added performance. Insurance group ratings are comparable, though the C-Class may have a small advantage. Both cars fall into higher groups typical for executive class models. 

Road tax is pegged to CO2 emissions so models with lower outputs attract cheaper tax rates. 

Servicing and maintenance at approved dealerships are comparable between the German brands when following scheduled intervals. BMW offers lower purchase prices that offset the C-Class's better resale values. Overall running expenses are very close, meaning drivers get similar long-term value from either model when accounting for depreciation, fuel, insurance, tax and upkeep costs.

Winner: Draw

The Verdict

The BMW 3 Series remains the sportier choice with incredible driving dynamics and lower starting prices, but the new C-Class makes big strides with sleek styling and a technology-focused interior. Mercedes also tops the 3 Series for space.

If you prioritise athletic driving dynamics, value and accessible performance, the BMW 3 Series is the best option. But buyers wanting comfort, technology, safety and overall luxury will be very happy with the Mercedes C-Class. Ultimately it comes down to your preferences. Both are outstanding choices that firmly occupy top spots in the compact executive category. 

Test driving each will help determine the right model for your needs. At the end of the day, you can't go wrong with either of these German icons. 

Take a look at our stock including BMW and Mercedes and find one that suits your needs. Test drive them back-to-back to determine the best fit for your needs and preferences.