3 Series vs C-Class
| BMW 3 Series<br>2024 | Mercedes-Benz C-Class<br>2024 | |
|---|---|---|
| Price from | £38,995 | £40,000 |
| Body type | Saloon | Saloon |
| Fuel | Petrol | Diesel |
| Engine | 2.0L TwinPower turbo petrol | 2.0-litre turbocharged diesel (C 220 d, mild hybrid) |
| Power | 184 hp | 200 PS (147 kW) |
| 0-62 mph | 7.4 seconds | — |
| Transmission | 8-speed automatic | 9G-Tronic 9-speed automatic |
| Fuel type | Petrol | — |
| Fuel economy | 42.8 mpg (combined) | 57.6 mpg (WLTP combined) |
| CO2 emissions | 149 g/km | — |
| Seats | 5 | — |
| Boot space | 480 litres | 455 litres |
| Drivetrain | Rear-wheel drive | — |
| 0-60 mph | — | 7.3 seconds |
| Top speed | — | 150 mph |
| CO2 | — | 129 g/km |
| Length | — | 4751 mm |
| Drive | — | Rear-wheel drive |
| Owner rating | — | — |
Some rivalries are so old they have their own weather system. BMW versus Mercedes in the compact executive class has been the defining contest of the company-car era for forty years, argued over in offices from Slough to Leeds. In 2024 the two contenders line up at exactly the same price — £40,000 apiece — which strips the debate to its purest form: no discounts, no excuses, just the cars.
And they could hardly be more different in philosophy. The BMW 3 Series is a petrol car with around 184 hp, reaching 60 mph in about 7.1 seconds. The Mercedes C-Class is a diesel with 200 PS, taking about 7.3 seconds. The BMW is a fraction quicker and, as BMWs are, the keener driver's tool — sharper steering, better balance, the car you take the long way home in. The Mercedes counters with torque and composure: that diesel pulls effortlessly, the cabin is the quieter place to spend two hours, and it simply feels more grown-up.
Then comes the number that reshapes the whole contest: fuel. The C-Class diesel returns 57.6 mpg; the BMW petrol manages around 44 mpg. For 8,000 miles a year that is £916 versus £1,199 — a £283 annual gap that widens with every extra mile. Insurance (£720 each), maintenance (£510 each), and tax (£190 each) are identical, so the diesel's economy flows straight to the bottom line. Five-year true cost: £36,880 for the Mercedes against £38,295 for the BMW. Monthly, £615 versus £638; on 48-month finance both ask £911.33, since the purchase prices match.
Buyer profiles are well-established tribes. The BMW suits the driving enthusiast who values steering feel and chassis balance above all, and who does moderate mileage where the petrol's thirst never really bites. The Mercedes suits the high-mileage executive — the rep covering the M1 weekly — for whom 57.6 mpg and a hushed cabin are worth more than lap times. The third buyer, the image-conscious, will choose on badge affection alone, and neither choice needs defending.
Our pick is the Mercedes C-Class, with one condition attached. For the way most people actually use a £40,000 saloon — long journeys, motorways, big annual mileages — the diesel's £283-a-year fuel advantage and £1,415 five-year saving are decisive, and it gives up almost nothing in pace. But if you are a genuine driving enthusiast doing modest miles, the BMW 3 Series remains the better driver's car, and no spreadsheet will talk you out of it. Choose with your mileage, not your heart.
BMW 3 Series review → Mercedes-Benz C-Class review →