Mercedes-Benz C-Class vs Audi A3
The Audi A3 is the more efficient of the two: it reaches 39 mpg combined versus 30 mpg for the Mercedes-Benz C-Class, a 9 mpg advantage and costs about $650 less per year to fuel.
Across 5 measured categories, the Audi A3 leads in 5. Figures are EPA test data, not manufacturer claims.
2015–2027
Mercedes-Benz C-Class
Subcompact Cars · 123 configurations
Head-to-head specifications
| Metric | Mercedes-Benz C-Class | Audi A3 |
|---|---|---|
| Best combined MPG | 30 mpg | 39 mpg ✓ |
| Best city MPG | 28 mpg | 37 mpg ✓ |
| Best highway MPG | 36 mpg | 41 mpg ✓ |
| Lowest annual fuel costEPA estimate at 15,000 miles per year | $2,550 | $1,900 ✓ |
| Lowest CO2 output | 215 g/mi | 138 g/mi ✓ |
| Engines offered | SIDI; Mild Hybrid, SIDI & PFI, SIDI; PHEV, SIDI | SIDI, SIDI; Mild Hybrid, SIDI; PHEV, 2.0 |
| Transmissions | Automatic 9-spd, Automatic 7-spd | Automatic (AM-S7), Automatic (AM-S6) |
| Drivetrains | All-Wheel Drive, Rear-Wheel Drive, 4-Wheel Drive | All-Wheel Drive, Front-Wheel Drive, 4-Wheel Drive |
| Fuel types | Premium, Premium and Electricity | Premium, Regular, Premium and Electricity |
| EPA class | Subcompact Cars | Subcompact Cars |
| Years covered | 2015–2027 | 2015–2026 |
| Configurations on record | 123 | 36 |
Source: EPA fuel economy records via fueleconomy.gov. Best-case values across all recorded configurations for each model.
C-Class vs A3: common questions
Which is better on gas, the Mercedes-Benz C-Class or the Audi A3?
The Audi A3 is the more efficient of the two: it reaches 39 mpg combined versus 30 mpg for the Mercedes-Benz C-Class, a 9 mpg advantage and costs about $650 less per year to fuel.
Which costs less to run per year?
By EPA estimates at 15,000 miles a year, the Audi A3 runs about $1,900 a year in fuel at its most efficient configuration, versus about $2,550 for the Mercedes-Benz C-Class — a difference of roughly $650 per year.
What engines do the C-Class and A3 offer?
Mercedes-Benz C-Class: SIDI; Mild Hybrid, SIDI & PFI, SIDI; PHEV, SIDI. Audi A3: SIDI, SIDI; Mild Hybrid, SIDI; PHEV, 2.0.
Are they in the same vehicle class?
Yes — the EPA classifies both the Mercedes-Benz C-Class and the Audi A3 as Subcompact Cars, so they compete directly.
More C-Class comparisons
Comparison id: mercedes-benz-c-class-vs-audi-a3