2021 head-to-head · Subcompact Car

2021 Audi S5 vs Mercedes-Benz C-Class

MPG, range and what each one really costs you to fuel, from official EPA ratings and recalculated with your own gas and electricity prices.

Swap sides
✓ Cheaper to run
$2,576/ year to fuel
23 MPG
✓ Cheaper to run
$2,194/ year to fuel
27 MPG

The 2021 Mercedes-Benz C-Class is the cheaper one to run. Driving 15,000 miles a year with $3.95/gal premium gas, it costs about $2,194 a year to fuel (27 MPG), versus $2,576 for the 2021 Audi S5 (23 MPG). That's roughly $382 a year, or about $1,908 over five years.

Your numbers

Change these to match your driving and local prices. Every figure and chart on this page updates.

Fuel cost over 10 years

  • Audi S5
  • Mercedes-Benz C-Class

Side by side

Audi S5Mercedes-Benz C-Class
$2,576 Your annual fuel cost $2,194
23 MPG Combined efficiency 27 MPG
20 MPG City 24 MPG
28 MPG Highway 33 MPG
84 cu ft Passenger volume 79 cu ft
11 cu ft Cargo volume 10 cu ft
380 g/mi Tailpipe CO₂ (g/mi) 330 g/mi
5/10 EPA fuel economy score 6/10
5/10 EPA greenhouse gas score 6/10
Gas Powertrain Gas
Premium gasoline Fuel Premium gasoline
3.0L 6-cyl turbo Engine / motor 2.0L 4-cyl turbo
8-speed automatic Transmission 9-speed automatic
AWD Drivetrain RWD

✓ marks the better value. EPA scores run 1–10 (10 is best). Volumes come from the EPA interior volume index and aren't published for every body style.

Audi S5 vs Mercedes-Benz C-Class across model years

  • Audi S5
  • Mercedes-Benz C-Class

Annual fuel cost of the most efficient configuration of each model year, at your prices. Click a point to open that year.

How they differ

Per EPA interior volume figures, the Audi S5 has more passenger space (84 vs. 79 cu ft); the Audi S5 has more cargo space (11 vs. 10 cu ft).

Among 34 2021 subcompact cars, the Audi S5 ranks 23rd and the Mercedes-Benz C-Class 16th for lowest fuel cost.

Frequently asked questions

Which is more fuel-efficient, the 2021 Audi S5 or the 2021 Mercedes-Benz C-Class?

Measured by cost to drive, the Mercedes-Benz C-Class. The Audi S5 is rated 23 MPG combined and the Mercedes-Benz C-Class 27 MPG (EPA, most efficient configuration of each).

How much does it cost to fuel the 2021 Audi S5 vs. the Mercedes-Benz C-Class per year?

At 15,000 miles a year with $3.95/gal premium gas, about $2,576 for the Audi S5 and $2,194 for the Mercedes-Benz C-Class.

Which has more cargo space?

The Audi S5, with 11 cu ft of luggage volume versus 10 cu ft (EPA interior volume index).

Audi S5 vs Mercedes-Benz C-Class in other years

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