2015 head-to-head · Midsize Car

2015 Audi S6 vs Infiniti Q40

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
$2,962/ year to fuel
20 MPG

AWD · 4.0L 8-cyl turbo · 7-speed dual-clutch · 20 MPG

✓ Cheaper to run
$2,693/ year to fuel
22 MPG

The 2015 Infiniti Q40 is the cheaper one to run. Driving 15,000 miles a year with $3.95/gal premium gas, it costs about $2,693 a year to fuel (22 MPG), versus $2,962 for the 2015 Audi S6 (20 MPG). That's roughly $269 a year, or about $1,347 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 S6
  • Infiniti Q40

Side by side

Audi S6Infiniti Q40
$2,962 Your annual fuel cost $2,693
20 MPG Combined efficiency 22 MPG
17 MPG City 19 MPG
27 MPG Highway 27 MPG
98 cu ft Passenger volume 99 cu ft
16 cu ft Cargo volume 14 cu ft
441 g/mi Tailpipe CO₂ (g/mi) 412 g/mi
5/10 EPA fuel economy score 5/10
5/10 EPA greenhouse gas score 5/10
Gas Powertrain Gas
Premium gasoline Fuel Premium gasoline
4.0L 8-cyl turbo Engine / motor 3.7L 6-cyl
7-speed dual-clutch Transmission 7-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 S6 vs Infiniti Q40 across model years

  • Audi S6
  • Infiniti Q40

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 S6 has more cargo space (16 vs. 14 cu ft).

Among 69 2015 midsize cars, the Audi S6 ranks 59th and the Infiniti Q40 55th for lowest fuel cost.

Frequently asked questions

Which is more fuel-efficient, the 2015 Audi S6 or the 2015 Infiniti Q40?

Measured by cost to drive, the Infiniti Q40. The Audi S6 is rated 20 MPG combined and the Infiniti Q40 22 MPG (EPA, most efficient configuration of each).

How much does it cost to fuel the 2015 Audi S6 vs. the Infiniti Q40 per year?

At 15,000 miles a year with $3.95/gal premium gas, about $2,962 for the Audi S6 and $2,693 for the Infiniti Q40.

Which has more cargo space?

The Audi S6, with 16 cu ft of luggage volume versus 14 cu ft (EPA interior volume index).

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