2015 head-to-head · Large Car

2015 Audi A8 vs Cadillac XTS

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
$2,693/ year to fuel
22 MPG
✓ Cheaper to run
$2,214/ year to fuel
21 MPG

The 2015 Cadillac XTS is the cheaper one to run. Driving 15,000 miles a year with $3.95/gal premium gas and $3.10/gal regular gas, it costs about $2,214 a year to fuel (21 MPG), versus $2,693 for the 2015 Audi A8 (22 MPG). That's roughly $479 a year, or about $2,394 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 A8
  • Cadillac XTS

Side by side

Audi A8Cadillac XTS
$2,693 Your annual fuel cost $2,214
22 MPG Combined efficiency 21 MPG
18 MPG City 18 MPG
30 MPG Highway 28 MPG
100 cu ft Passenger volume 104 cu ft
15 cu ft Cargo volume 18 cu ft
401 g/mi Tailpipe CO₂ (g/mi) 419 g/mi
5/10 EPA fuel economy score 5/10
5/10 EPA greenhouse gas score 5/10
Gas Powertrain Gas
Premium gasoline Fuel Regular gasoline
4.0L 8-cyl turbo Engine / motor 3.6L 6-cyl
8-speed automatic Transmission 6-speed automatic
AWD Drivetrain FWD

✓ 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 A8 vs Cadillac XTS across model years

  • Audi A8
  • Cadillac XTS

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 Cadillac XTS has more passenger space (104 vs. 100 cu ft); the Cadillac XTS has more cargo space (18 vs. 15 cu ft).

Among 29 2015 large cars, the Audi A8 ranks 21st and the Cadillac XTS 16th for lowest fuel cost.

Frequently asked questions

Which is more fuel-efficient, the 2015 Audi A8 or the 2015 Cadillac XTS?

Measured by cost to drive, the Cadillac XTS. The Audi A8 is rated 22 MPG combined and the Cadillac XTS 21 MPG (EPA, most efficient configuration of each).

How much does it cost to fuel the 2015 Audi A8 vs. the Cadillac XTS per year?

At 15,000 miles a year with $3.95/gal premium gas and $3.10/gal regular gas, about $2,693 for the Audi A8 and $2,214 for the Cadillac XTS.

Which has more cargo space?

The Cadillac XTS, with 18 cu ft of luggage volume versus 15 cu ft (EPA interior volume index).

Audi A8 vs Cadillac XTS in other years

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