Audi A4 vs Mercedes-Benz C-Class: B9 against W206
Updated Report an error By Felix Hartmann
Audi · 2015–2024
A4 B9
- Power
- 140 kW190 PS
- 0–100 km/h
- 7.7 s
- Top speed
- 210 km/h
- Kerb mass
- 1,565 kg
Mercedes-Benz · 2021–present
C-Class W206
- Power
- 147 kW200 PS
- 0–100 km/h
- -
- Top speed
- -
- Kerb mass
- 1,824 kg
At a glance
Who suits what, worked out from the catalog figures of the versions above.
Categories won: A4 B9 1 C-Class W206 3
- Family Too close to call Boot: 460 l vs 455 l
- City C-Class W206 Consumption: 4.6 l/100 km vs 5.2 l/100 km
- Long trips C-Class W206 Range: 1,087 km vs 769 km (estimated)
- Performance A4 B9 Power per tonne: 90 kW/t vs 81 kW/t
- Running costs C-Class W206 Fuel per year: €1,140 vs €1,290 (estimated)
Verdict Opinion
The A4 B9 is the choice for drivers who value engines. Its V6 diesels with up to 700 Nm and the V6 RS 4 Avant are no longer available from Mercedes. As a used car the A4 comes in a wide spread of outputs and three body styles.
The C-Class is the more modern car in almost every other respect. It is newer by six years and the C 300 e offers about 100 km of electric range. Its diesel has more combined output than the 40 TDI, and its Euro NCAP scores are higher in every category listed here.
- Felix Hartmann
The A4 and the C-Class have competed for the same company-car and private buyers for decades. This comparison covers the two most recent generations. Audi launched the A4 B9 at the Frankfurt Motor Show in September 2015, about 120 kg lighter than its predecessor, and sold it as a saloon, Avant and allroad. The 2025 model year is the last for the A4 name, as Audi's new naming scheme moves its successor to the A5 badge. Mercedes-Benz presented the W206 C-Class on 23 February 2021 and started production in March 2021 in Bremen, East London and Beijing.
In short: the Audi A4 offers six-cylinder diesels and a V6 RS 4 that the four-cylinder-only C-Class no longer has. The Mercedes-Benz C-Class is the newer car, with a 100 km plug-in hybrid, rear-axle steering and higher Euro NCAP scores. The model histories are on our Audi A4 and Mercedes-Benz C-Class pages.
Audi A4 vs Mercedes-Benz C-Class: what separates them
Mainstream diesels: 40 TDI against C 220 d
The A4 40 TDI uses a 2.0-litre diesel with 140 kW (190 PS) and 400 Nm. The C 220 d has 147 kW (200 PS) from its engine and an integrated 48-volt starter-generator that adds 15 kW, for 162 kW (220 PS) combined. Mercedes therefore leads at this level by 22 kW of combined output.
Six cylinders against four
Audi kept V6 engines in the B9 range: the 45 TDI with 160 kW and 500 Nm, the 50 TDI quattro with 200 kW and 600 Nm, and the S4 TDI with 255 kW and 700 Nm. North American buyers got only petrol engines, including a 260 kW 3.0 V6 TFSI in their S4. The W206 C-Class uses four-cylinder engines across its petrol, diesel and plug-in hybrid versions; the AMG C 43 4MATIC reaches 320 kW (435 PS) from four cylinders.
Petrol engines
The A4 35 TFSI has 110 kW and 250 Nm, the 40 TFSI 140 kW and the 45 TFSI 185 kW with 370 Nm. The C 200 has 150 kW (204 PS) and the C 300 190 kW (258 PS).
Plug-in hybrid only at Mercedes
The B9's engine list contains no plug-in hybrid. The C 300 e combines a petrol engine with a 25.4 kWh battery for 245 kW (333 PS) and about 100 km of electric range. That is a strong argument for company-car drivers who can charge at work or at home.
RS 4 against C 63
The RS 4 Avant has a 2.9-litre V6 TFSI with 331 kW (450 PS) and 600 Nm. The Mercedes-AMG C 63 S E Performance takes the opposite approach: a 2.0-litre four-cylinder with 350 kW alone and 500 kW (680 PS) combined with its electric motor and 6.1 kWh battery.
Size and chassis
The C-Class saloon and estate are 4,751 mm long on a 2,865 mm wheelbase. Optional rear-axle steering turns the rear wheels by up to 2.5 degrees and cuts the turning circle by 0.4 m to 10.6 m. Inside, the W206 has a 12.3-inch instrument display and an 11.9-inch central touchscreen.
Euro NCAP
The A4 earned five stars in 2015 with 89% for adult occupants, 87% for children and 75% for pedestrians. The C-Class, tested in 2022, scored 93%, 89% and 80% in the same categories.
Race Stats side by side
Each figure is a 0–100 score from the catalog numbers, the same as on the 1CARS Race cards. PI is the overall performance index (100–999) and its class D–S.
| Stat | A4 B9 | C-Class W206 |
|---|---|---|
| PI | B · 526 | B · 521 |
| Power | 47 | 43 |
| Grip | 36 | 36 |
| Handling | 67 | 62 |
| Top speed | 42 | 53 |
| Launch | 44 | 44 |
Grip and handling are estimates from drive type, weight, height and body (hover a figure to see where it comes from). 1CARS Race
Who wins a race?
Quarter-mile (402 m) drag from a standing start, dry road, no reaction time - the 1CARS Race physics on the catalog figures of these versions.
- 1 C-Class W206C-Class W206 · C 220 d · diesel · 147 kW (200 PS) 15.55 sat 142 km/h
- 2 A4 B9A4 B9 · 40 TDI · diesel · 140 kW (190 PS) 15.64 sat 144 km/h · +0.09 s
Size and weight
Side view to scale, all cars from the front bumper.
| A4 B9 | C-Class W206 | |
|---|---|---|
| Length | 4,726 mm186.1 in † | 4,751 mm187.0 in +25 mm +1.0 in +0.5% |
| Width | 1,842 mm72.5 in † | 1,820 mm71.7 in −22 mm −0.9 in −1.2% |
| Height | 1,427 mm56.2 in † | 1,438 mm56.6 in +11 mm +0.4 in +0.8% |
| Wheelbase | 2,820 mm111.0 in † | 2,865 mm112.8 in +45 mm +1.8 in +1.6% |
| Kerb weight | 1,565 kg3,450 lb | 1,824 kg4,021 lb +259 kg +571 lb +16.5% |
| Boot | 460 l16.2 cu ft | 455 l16.1 cu ft † −5 l −0.2 cu ft −1.1% |
| Fuel tank | 40 l10.6 gal US | 50 l13.2 gal US † +10 l +2.6 gal US +25.0% |
| Fits a standard garage? | Yes | Yes |
Difference vs A4 B9 (±). Garage check: a standard single garage takes a car up to about 5.0 m (16 ft 5 in) long and 1.9 m (6 ft 3 in) wide (width as listed in the catalog; some makers include the mirrors). Leave about 0.6 m (2 ft) to open the doors. † from another version of this generation.
Full specifications
| Audi A4 | Mercedes-Benz C-Class | |
|---|---|---|
| General | ||
| Version | A4 B9 · 40 TDI · diesel · 140 kW (190 PS) | C-Class W206 · C 220 d · diesel · 147 kW (200 PS) |
| Production years | 2015–2024 | 2021–present |
| Body | Sedan | Sedan |
| Country | Germany | Germany |
| Performance | ||
| Power Why it matters: More power means stronger acceleration and easier overtaking, especially with a full load. | 140 kW (190 PS) 188 hp | 147 kW (200 PS) 197 hp Better |
| Power, all versions | 66–331 kW (90–450 PS) 89–444 hp | 55–270 kW (75–367 PS) 74–362 hp |
| Torque Why it matters: Torque is the pulling force you feel when accelerating from low revs, towing or climbing hills. | 400 Nm 295 lb-ft | No data |
| 0–100 km/h Why it matters: A shorter 0–100 km/h time means quicker getaways and safer merging onto fast roads. | 7.7 s | No data |
| Top speed Why it matters: Top speed hints at how relaxed the car is at motorway speeds, even if you never reach it. | 210 km/h 130 mph | No data |
| Power per tonne | 90 kW/t 109 hp/ton calculated Better | 81 kW/t 98 hp/ton calculated |
| Engine and transmission | ||
| Fuel | Diesel | Diesel |
| Engine | 2,000 cc 2.0 l | 1,993 cc · 4 cyl 2.0 l |
| Drive | No data | Rear-wheel drive |
| Dimensions and weight | ||
| Length | 4,726 mm 186.1 in † | 4,751 mm 187.0 in |
| Width | 1,842 mm 72.5 in † | 1,820 mm 71.7 in |
| Height | 1,427 mm 56.2 in † | 1,438 mm 56.6 in |
| Wheelbase | 2,820 mm 111.0 in † | 2,865 mm 112.8 in |
| Kerb weight Why it matters: A lighter car is usually more agile and uses less energy. | 1,565 kg 3,450 lb Better | 1,824 kg 4,021 lb |
| Boot Why it matters: A bigger boot fits more luggage, shopping or a pram. | 460 l 16.2 cu ft | 455 l 16.1 cu ft † |
| Fuel tank Why it matters: A larger tank means more distance between fuel stops. | 40 l 10.6 gal US | 50 l 13.2 gal US † Better |
| Economy and running costs | ||
| Fuel consumption Why it matters: Lower consumption cuts running costs and CO₂ emissions on every trip. | 5.2 l/100 km 45.2 mpg US | 4.6 l/100 km 51.1 mpg US Better |
| CO₂ | 135 g/km | 120 g/km Better |
| Fuel cost per year | €1,290/year estimated | €1,140/year estimated Better |
| Range on a full tank | 769 km 478 mi estimated | 1,087 km 675 mi estimated Better |
| Safety | ||
| Euro NCAP | No data | ★★★★★ (2022) |
These cars do not differ in the data we have.
Equal rows hidden (3): Body, Country, Fuel.
Better marks the stronger figure - only for measurable specs (power, torque, 0–100 km/h, consumption, boot, weight).
Estimated at 15,000 km a year with fuel at €1.65/l diesel. † from another version of this generation.
In plain words
Mercedes-Benz C-Class has more power: 147 kW (200 PS) against 140 kW (190 PS) for Audi A4. Mercedes-Benz C-Class is 25 mm longer than Audi A4 (4,751 mm vs 4,726 mm). Audi A4 is lighter by 259 kg (1,565 kg vs 1,824 kg). Audi A4 has the bigger boot: 460 l against 455 l. At 15,000 km a year, fuel would cost about €1,290 (Audi A4), €1,140 (Mercedes-Benz C-Class) (estimated). Mercedes-Benz C-Class is the older design (from 1993); Audi A4 arrived in 1994. Mercedes-Benz C-Class is still in production; Audi A4 is not. On the catalog figures, the Mercedes-Benz C-Class is the pick for city, long trips and running costs; the Audi A4 is the pick for performance. Our catalog has no 0–100 km/h for the Mercedes-Benz C-Class yet, so some checks above leave it out.
Which one to choose
Choose the Audi A4 if you want a six-cylinder diesel with high torque, the RS 4 Avant's V6, or a well-equipped used saloon or Avant from the last years of the A4 name.
Choose the Mercedes-Benz C-Class if you plan to drive on electricity in a C 300 e, want rear-axle steering for tight streets, or prefer the newer car with the better crash-test scores.
Both also meet BMW on 1cars: Audi A4 vs BMW 3 Series and BMW 3 Series vs Mercedes-Benz C-Class.
Frequently asked questions
Is the Audi A4 still made?
The 2025 model year is the last for the A4 name. Under Audi's new naming scheme its successor is sold as the A5.
Which diesel is stronger, the A4 40 TDI or the C 220 d?
The C 220 d: 147 kW from the engine plus 15 kW from its starter-generator, 162 kW combined, against 140 kW (190 PS) for the A4 40 TDI.
Does the C-Class have a six-cylinder engine?
Not in the W206 generation. Its petrol, diesel and plug-in hybrid engines are all four-cylinder units, including the 320 kW AMG C 43 and the 500 kW C 63 S E Performance.
Which scored better in Euro NCAP?
The C-Class: 93% for adult occupants in 2022 against 89% for the A4 in 2015, and higher scores for children and pedestrians too.