Mazda CX-9 vs Subaru Ascent: Specs Compared
Also searched as Subaru Ascent vs Mazda CX-9 specs — both orientations show this same side-by-side comparison.
The Mazda CX-9 is the more efficient of the two: it reaches 24 mpg combined versus 23 mpg for the Subaru Ascent, a 1 mpg advantage and costs about $100 less per year to fuel.
Across 5 measured categories, the Mazda CX-9 leads in 5. Figures are EPA test data, not manufacturer claims.
2015–2023
Mazda CX-9
Small Sport Utility Vehicle 4WD · 16 configurations
2019–2027
Subaru Ascent
Standard Sport Utility Vehicle 4WD · 18 configurations
Head-to-head specifications
| Metric | Mazda CX-9 | Subaru Ascent |
|---|---|---|
| Best combined MPG | 24 mpg ✓ | 23 mpg |
| Best city MPG | 22 mpg ✓ | 21 mpg |
| Best highway MPG | 28 mpg ✓ | 27 mpg |
| Lowest annual fuel costEPA estimate at 15,000 miles per year | $2,550 ✓ | $2,650 |
| Lowest CO2 output | 362 g/mi ✓ | 384 g/mi |
| Engines offered | SIDI, 3.7 | SIDI |
| Transmissions | Automatic (S6) | Automatic (AV-S8) |
| Drivetrains | 4-Wheel Drive, Front-Wheel Drive | All-Wheel Drive |
| Fuel types | Regular | Regular |
| EPA class | Small Sport Utility Vehicle 4WD | Standard Sport Utility Vehicle 4WD |
| Years covered | 2015–2023 | 2019–2027 |
| Configurations on record | 16 | 18 |
Source: EPA fuel economy records via fueleconomy.gov. Best-case values across all recorded configurations for each model.
Mazda CX-9 vs Subaru Ascent dimensions and size
The Mazda CX-9 is 2.8 inches longer than the Subaru Ascent on a wheelbase 1.6 inches longer, and 33.1 lbs lighter. Both clear the roughly 200 inches of usable length in a standard single garage bay.
| Dimension | Mazda CX-9 (2023) | Subaru Ascent (2026) | Difference |
|---|---|---|---|
| Length | 199.6 in | 196.9 in | 2.8 in |
| Width (excl. mirrors) | 77.6 in | 71.7 in | 5.9 in |
| Height | 67.7 in | 76 in | 8.3 in |
| Wheelbase | 115.4 in | 113.8 in | 1.6 in |
| Curb weight | 4,387 lbs | 4,420 lbs | 33 lbs |
Width excludes mirrors; add 8–12 inches for mirrors out. Figures are for the newest model year on record for each vehicle. See both drawn to scale.
Mazda CX-9 vs Subaru Ascent: what the numbers mean
Running cost over five years: at the EPA's 15,000-mile-a-year assumption the Mazda CX-9 burns about $2,550 of fuel annually against $2,650 for the Subaru Ascent. That $100 yearly gap compounds to roughly $500 over five years and $800 over eight — often more than the price difference between two trims of the same vehicle, and the single largest running-cost line item separating these two.
City and highway economy: the Mazda CX-9 leads in both cycles — 22 mpg city and 28 mpg highway against 21 and 27 mpg — so its fuel-efficiency advantage holds whether you commute in traffic or cover long highway miles.
Powertrain choice: the Mazda CX-9 is recorded with 2 distinct engine configurations (SIDI, 3.7), the Subaru Ascent with 1 (SIDI). Across 16 recorded Mazda CX-9 configurations and 18 for the Subaru Ascent, the wider the engine spread the more the real-world fuel efficiency depends on which version you actually buy, so check the specific model year and drivetrain rather than the headline number.
Drivetrain and class: the Mazda CX-9 is offered with 4-Wheel Drive, Front-Wheel Drive, the Subaru Ascent with All-Wheel Drive. All-wheel drive typically costs one to two mpg combined against the same vehicle in front- or rear-wheel drive, which is worth remembering when the gap between these two is small. The EPA classes them as Small Sport Utility Vehicle 4WD and Standard Sport Utility Vehicle 4WD respectively — the class drives the interior volume, cargo space and passenger space each one is measured against.
Tailpipe emissions: at their cleanest configurations the Mazda CX-9 emits 362 g/mile of CO2 versus 384 g/mile for the Subaru Ascent. Emissions track fuel consumption almost exactly, so the cleaner vehicle here is also the cheaper one to fuel.
CX-9 vs Ascent: common questions
Which is better on gas, the Mazda CX-9 or the Subaru Ascent?
The Mazda CX-9 is the more efficient of the two: it reaches 24 mpg combined versus 23 mpg for the Subaru Ascent, a 1 mpg advantage and costs about $100 less per year to fuel.
Which costs less to run per year?
By EPA estimates at 15,000 miles a year, the Mazda CX-9 runs about $2,550 a year in fuel at its most efficient configuration, versus about $2,650 for the Subaru Ascent — a difference of roughly $100 per year.
What engines do the CX-9 and Ascent offer?
Mazda CX-9: SIDI, 3.7. Subaru Ascent: SIDI.
Are they in the same vehicle class?
The EPA classifies the Mazda CX-9 as Small Sport Utility Vehicle 4WD and the Subaru Ascent as Standard Sport Utility Vehicle 4WD, so they aren't a like-for-like match on size.
More CX-9 comparisons
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Comparison id: mazda-cx-9-vs-subaru-ascent