2015 head-to-head · Midsize Car
2015 Audi S8 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.
AWD · 4.0L 8-cyl turbo · 8-speed automatic · 20 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 S8 (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 S8
- Infiniti Q40
Side by side
| Audi S8 | Infiniti Q40 | |
|---|---|---|
| $2,962 | Your annual fuel cost | $2,693 |
| 20 MPG | Combined efficiency | 22 MPG |
| 16 MPG | City | 19 MPG |
| 27 MPG | Highway | 27 MPG |
| 100 cu ft | Passenger volume | 99 cu ft |
| 15 cu ft | Cargo volume | 14 cu ft |
| 452 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 |
| 8-speed automatic | 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 S8 vs Infiniti Q40 across model years
- Audi S8
- 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 S8 has more cargo space (15 vs. 14 cu ft).
Among 69 2015 midsize cars, the Audi S8 ranks 60th and the Infiniti Q40 55th for lowest fuel cost.
Frequently asked questions
Which is more fuel-efficient, the 2015 Audi S8 or the 2015 Infiniti Q40?
Measured by cost to drive, the Infiniti Q40. The Audi S8 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 S8 vs. the Infiniti Q40 per year?
At 15,000 miles a year with $3.95/gal premium gas, about $2,962 for the Audi S8 and $2,693 for the Infiniti Q40.
Which has more cargo space?
The Audi S8, with 15 cu ft of luggage volume versus 14 cu ft (EPA interior volume index).
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