2018 head-to-head · Midsize Car

2018 Audi S6 vs Cadillac CTS-V

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
$3,292/ year to fuel
18 MPG

AWD · 4.0L 8-cyl turbo · 7-speed dual-clutch · 18 MPG

✓ Cheaper to run
$3,485/ year to fuel
17 MPG

RWD · 6.2L 8-cyl supercharged · 8-speed automatic · 17 MPG

The 2018 Audi S6 is the cheaper one to run. Driving 15,000 miles a year with $3.95/gal premium gas, it costs about $3,292 a year to fuel (18 MPG), versus $3,485 for the 2018 Cadillac CTS-V (17 MPG). That's roughly $194 a year, or about $968 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
  • Cadillac CTS-V

Side by side

Audi S6Cadillac CTS-V
$3,292 Your annual fuel cost $3,485
18 MPG Combined efficiency 17 MPG
16 MPG City 14 MPG
24 MPG Highway 21 MPG
98 cu ft Passenger volume 97 cu ft
16 cu ft Cargo volume 13 cu ft
480 g/mi Tailpipe CO₂ (g/mi) 530 g/mi
3/10 EPA fuel economy score 3/10
3/10 EPA greenhouse gas score 3/10
Gas Powertrain Gas
Premium gasoline Fuel Premium gasoline
4.0L 8-cyl turbo Engine / motor 6.2L 8-cyl supercharged
7-speed dual-clutch Transmission 8-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 Cadillac CTS-V across model years

  • Audi S6
  • Cadillac CTS-V

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. 13 cu ft).

Among 74 2018 midsize cars, the Audi S6 ranks 66th and the Cadillac CTS-V 70th for lowest fuel cost.

Frequently asked questions

Which is more fuel-efficient, the 2018 Audi S6 or the 2018 Cadillac CTS-V?

Measured by cost to drive, the Audi S6. The Audi S6 is rated 18 MPG combined and the Cadillac CTS-V 17 MPG (EPA, most efficient configuration of each).

How much does it cost to fuel the 2018 Audi S6 vs. the Cadillac CTS-V per year?

At 15,000 miles a year with $3.95/gal premium gas, about $3,292 for the Audi S6 and $3,485 for the Cadillac CTS-V.

Which has more cargo space?

The Audi S6, with 16 cu ft of luggage volume versus 13 cu ft (EPA interior volume index).

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