2021 Subaru Crosstrek Transmission & Axle Gear Ratios

Transmission gear ratios

The 2021 Subaru Crosstrek offers two primary transmission options: a 6-speed manual transmission and a Lineartronic Continuously Variable Transmission (CVT).

6-Speed Manual Transmission

Lineartronic CVT

Available axle ratios

The 2021 Subaru Crosstrek comes with different axle ratios depending on the transmission and trim level. It's important to note that all Crosstrek models are equipped with Subaru's Symmetrical All-Wheel Drive, so these ratios apply to both the front and rear differentials.

How to identify your axle ratio

Unlike some domestic manufacturers that use RPO codes on door jamb stickers or axle tags, Subaru typically does not provide an easily identifiable axle code for the differential ratio on a visible sticker. The axle ratio is inherent to the transmission type and engine. For the 2021 Crosstrek:

• If you have the 6-speed manual transmission: Your axle ratio is 4.444.
• If you have the Lineartronic CVT: Your axle ratio is 3.700.

If you need to confirm this for any reason, a Subaru dealership service department can provide the exact specifications for your vehicle using your VIN.

Towing vs MPG impact

The axle ratio plays a significant role in determining a vehicle's balance between towing capability and fuel efficiency. Generally speaking:

• Numerically higher axle ratios (e.g., 4.444): These ratios mean the engine has to turn more times to rotate the wheels a single revolution. This results in more torque at the wheels, providing better acceleration and increased towing capacity. However, it also means the engine will be revving higher at any given speed, leading to lower fuel economy. The 6-speed manual Crosstrek with its 4.444 ratio is slightly better for off-road excursions and situations where more immediate power is desired, albeit at the cost of some MPG.

• Numerically lower axle ratios (e.g., 3.700): These ratios allow the engine to turn fewer times for a single wheel revolution. This reduces engine RPMs at cruising speeds, significantly improving fuel economy and providing a quieter ride on the highway. The CVT-equipped Crosstrek benefits from its 3.700 ratio, offering a more economical and refined driving experience for daily commuting and longer trips.

For the 2021 Crosstrek, the difference in axle ratios between the manual and CVT models reflects their intended applications. The manual, often chosen by enthusiasts, offers a more engaged driving experience and slightly more robust performance at the cost of fuel economy, while the CVT prioritizes efficiency and convenience.

Common issues

Subaru drivetrains, particularly the differentials, are generally known for their robustness. However, like any mechanical component, they can experience issues over time. Specific to axle components, some potential issues, though not widely reported as common for the 2021 Crosstrek, could include:

• Ring and pinion whine: This is often heard as a howling or whining noise that changes with vehicle speed, often most noticeable at specific speeds or during acceleration/deceleration. It can be caused by worn gears, improper gear mesh during installation, or insufficient lubricant.
• Carrier bearing wear: Bearings within the differential can wear out, leading to growling or rumbling noises, especially when turning or accelerating. If left unaddressed, this can lead to more significant damage.
• Limited-slip clutch wear (if applicable): While the Crosstrek utilizes a viscous-coupling center differential and open front/rear differentials with electronic traction control, if a limited-slip differential were present, worn clutch packs could lead to chattering or uneven power delivery, particularly in turns.

Regular maintenance, including checking and changing differential fluid at recommended intervals, is crucial for preventing these issues and ensuring the longevity of your drivetrain components.

Find a driveline shop on Repairius.