Audi A4 vs Mercedes-Benz C-Class: Specs Compared
Also searched as Mercedes-Benz C-Class vs Audi A4 specs — both orientations show this same side-by-side comparison.
The Audi A4 is the more efficient of the two: it reaches 31 mpg combined versus 30 mpg for the Mercedes-Benz C-Class, a 1 mpg advantage and costs about $100 less per year to fuel.
Across 5 measured categories, the Audi A4 leads in 3. Figures are EPA test data, not manufacturer claims.
2015–2027
Mercedes-Benz C-Class
Subcompact Cars · 123 configurations
Head-to-head specifications
| Metric | Audi A4 | Mercedes-Benz C-Class |
|---|---|---|
| Best combined MPG | 31 mpg ✓ | 30 mpg |
| Best city MPG | 27 mpg | 28 mpg ✓ |
| Best highway MPG | 37 mpg ✓ | 36 mpg |
| Lowest annual fuel costEPA estimate at 15,000 miles per year | $2,450 ✓ | $2,550 |
| Lowest CO2 output | 284 g/mi | 215 g/mi ✓ |
| Engines offered | SIDI; Mild Hybrid, SIDI, SIDI; FFV | SIDI; Mild Hybrid, SIDI & PFI, SIDI; PHEV, SIDI |
| Transmissions | Automatic (AM-S7), Manual 6-spd, Automatic (S8) | Automatic 9-spd, Automatic 7-spd |
| Drivetrains | All-Wheel Drive, Front-Wheel Drive | All-Wheel Drive, Rear-Wheel Drive, 4-Wheel Drive |
| Fuel types | Premium, Premium or E85 | Premium, Premium and Electricity |
| EPA class | Compact Cars | Subcompact Cars |
| Years covered | 2015–2025 | 2015–2027 |
| Configurations on record | 35 | 123 |
Source: EPA fuel economy records via fueleconomy.gov. Best-case values across all recorded configurations for each model.
Audi A4 vs Mercedes-Benz C-Class dimensions and size
The Mercedes-Benz C-Class is 1.2 inches longer than the Audi A4 on a wheelbase 2 inches longer, and 423.3 lbs heavier. Both clear the roughly 200 inches of usable length in a standard single garage bay.
| Dimension | Audi A4 (2025) | Mercedes-Benz C-Class (2026) | Difference |
|---|---|---|---|
| Length | 187.4 in | 188.6 in | 1.2 in |
| Width (excl. mirrors) | 72.8 in | 71.7 in | 1.2 in |
| Height | 56.3 in | 56.7 in | 0.4 in |
| Wheelbase | 111 in | 113 in | 2 in |
| Curb weight | 3,633 lbs | 4,057 lbs | 423 lbs |
Width excludes mirrors; add 8–12 inches for mirrors out. Figures are for the newest model year on record for each vehicle. See both drawn to scale.
Audi A4 vs Mercedes-Benz C-Class: what the numbers mean
Running cost over five years: at the EPA's 15,000-mile-a-year assumption the Audi A4 burns about $2,450 of fuel annually against $2,550 for the Mercedes-Benz C-Class. That $100 yearly gap compounds to roughly $500 over five years and $800 over eight — often more than the price difference between two trims of the same vehicle, and the single largest running-cost line item separating these two.
City versus highway split: the Mercedes-Benz C-Class is the stronger commuter at 28 mpg city, while the Audi A4 pulls ahead on the interstate at 37 mpg highway. If most of your driving is stop-and-go traffic the city figure is the one to weigh; for long-distance highway mileage the reverse is true, and the two vehicles effectively swap places depending on how you drive.
Powertrain choice: the Audi A4 is recorded with 3 distinct engine configurations (SIDI; Mild Hybrid, SIDI, SIDI; FFV), the Mercedes-Benz C-Class with 4 (SIDI; Mild Hybrid, SIDI & PFI, SIDI; PHEV). Across 35 recorded Audi A4 configurations and 123 for the Mercedes-Benz C-Class, the wider the engine spread the more the real-world fuel efficiency depends on which version you actually buy, so check the specific model year and drivetrain rather than the headline number.
Drivetrain and class: the Audi A4 is offered with All-Wheel Drive, Front-Wheel Drive, the Mercedes-Benz C-Class with All-Wheel Drive, Rear-Wheel Drive, 4-Wheel Drive. All-wheel drive typically costs one to two mpg combined against the same vehicle in front- or rear-wheel drive, which is worth remembering when the gap between these two is small. The EPA classes them as Compact Cars and Subcompact Cars respectively — the class drives the interior volume, cargo space and passenger space each one is measured against.
Tailpipe emissions: at their cleanest configurations the Mercedes-Benz C-Class emits 215 g/mile of CO2 versus 284 g/mile for the Audi A4. Emissions track fuel consumption almost exactly, so the cleaner vehicle here is also the cheaper one to fuel.
A4 vs C-Class: common questions
Which is better on gas, the Audi A4 or the Mercedes-Benz C-Class?
The Audi A4 is the more efficient of the two: it reaches 31 mpg combined versus 30 mpg for the Mercedes-Benz C-Class, a 1 mpg advantage and costs about $100 less per year to fuel.
Which costs less to run per year?
By EPA estimates at 15,000 miles a year, the Audi A4 runs about $2,450 a year in fuel at its most efficient configuration, versus about $2,550 for the Mercedes-Benz C-Class — a difference of roughly $100 per year.
What engines do the A4 and C-Class offer?
Audi A4: SIDI; Mild Hybrid, SIDI, SIDI; FFV. Mercedes-Benz C-Class: SIDI; Mild Hybrid, SIDI & PFI, SIDI; PHEV, SIDI.
Are they in the same vehicle class?
The EPA classifies the Audi A4 as Compact Cars and the Mercedes-Benz C-Class as Subcompact Cars, so they aren't a like-for-like match on size.
More A4 comparisons
More C-Class comparisons
Comparison id: audi-a4-vs-mercedes-benz-c-class