2026 head-to-head · Midsize Car

2026 Audi A6 vs Cadillac CT5

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

AWD · 3.0L 6-cyl turbo · 7-speed dual-clutch · 23 MPG

✓ Cheaper to run
$2,279/ year to fuel
26 MPG

The 2026 Cadillac CT5 is the cheaper one to run. Driving 15,000 miles a year with $3.95/gal premium gas, it costs about $2,279 a year to fuel (26 MPG), versus $2,576 for the 2026 Audi A6 (23 MPG). That's roughly $297 a year, or about $1,486 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 A6
  • Cadillac CT5

Side by side

Audi A6Cadillac CT5
$2,576 Your annual fuel cost $2,279
23 MPG Combined efficiency 26 MPG
20 MPG City 22 MPG
29 MPG Highway 31 MPG
98 cu ft Passenger volume 99 cu ft
13 cu ft Cargo volume 11 cu ft
387 g/mi Tailpipe CO₂ (g/mi) 346 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
3.0L 6-cyl turbo Engine / motor 2.0L 4-cyl turbo
7-speed dual-clutch Transmission 10-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 A6 vs Cadillac CT5 across model years

  • Audi A6
  • Cadillac CT5

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 A6 has more cargo space (13 vs. 11 cu ft).

Among 31 2026 midsize cars, the Audi A6 ranks 26th and the Cadillac CT5 25th for lowest fuel cost.

Frequently asked questions

Which is more fuel-efficient, the 2026 Audi A6 or the 2026 Cadillac CT5?

Measured by cost to drive, the Cadillac CT5. The Audi A6 is rated 23 MPG combined and the Cadillac CT5 26 MPG (EPA, most efficient configuration of each).

How much does it cost to fuel the 2026 Audi A6 vs. the Cadillac CT5 per year?

At 15,000 miles a year with $3.95/gal premium gas, about $2,576 for the Audi A6 and $2,279 for the Cadillac CT5.

Which has more cargo space?

The Audi A6, with 13 cu ft of luggage volume versus 11 cu ft (EPA interior volume index).

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