2019 Tesla Model X Transmission & Axle Gear Ratios

Transmission gear ratios

The 2019 Tesla Model X, unlike traditional internal combustion engine vehicles, utilizes a single-speed direct drive transmission for each of its electric motors. This design simplifies the drivetrain, eliminating the need for multiple gears found in conventional transmissions. Each motor (front and rear) is paired with its own fixed gear reduction unit.

This 9.73:1 ratio applies to both the front and rear drive units, providing a consistent power delivery across all trims of the 2019 Model X.

Available axle ratios

Since the Tesla Model X employs a direct drive system with integrated reduction gears, the concept of "axle ratios" as distinct, interchangeable components like in traditional ICE vehicles doesn't directly apply. The 9.73:1 reduction ratio within each drive unit serves the same function as a combined transmission gear and axle ratio. Therefore, all 2019 Tesla Model X trims share this common drive unit ratio.

How to identify your axle ratio

For the 2019 Tesla Model X, identifying a specific "axle ratio" as one might for a gasoline or diesel vehicle with a separate differential is not applicable. The drive units are sealed, integrated components, and the gear reduction ratio is standard across all models. There is no RPO sticker on the door jamb or a physical axle tag to consult for identifying different ratios. The best way to understand your vehicle's gearing is to reference the manufacturer specifications, which universally state the 9.73:1 reduction ratio for the drive units.

Towing vs MPG impact

In traditional vehicles, a numerically lower axle ratio generally results in better fuel economy due to lower engine RPMs at cruising speeds, while a numerically higher ratio provides greater torque multiplication for improved towing and acceleration but at the cost of efficiency. For the 2019 Tesla Model X, this dynamic is different due to its electric powertrain and single-speed reduction gear.

The fixed 9.73:1 ratio is engineered to provide a balanced approach, optimized for both efficient cruising and responsive acceleration, contributing to the impressive range and performance figures of the Model X. While a different ratio could theoretically be designed for more extreme ends of the spectrum (e.g., even higher for ultimate towing or lower for theoretical marginal range improvements), the chosen ratio represents an optimal balance for a versatile luxury SUV.

Increased towing with an electric vehicle primarily impacts battery consumption rather than requiring a different gear ratio to manage engine stress. The direct drive system delivers ample torque from a standstill, making it highly effective for towing without the need for multiple gears. However, towing will inherently reduce the vehicle's range due to increased energy demands.

Common issues

Unlike conventional drivetrains that suffer from issues like ring and pinion whine, carrier bearing failure, or limited-slip clutch wear, the Tesla Model X's integrated electric drive units are designed with fewer moving parts and different operational characteristics. While drive units are robust, like any mechanical component, they can experience issues. Potential concerns for Tesla drive units, though relatively uncommon, can include:

• Bearing noise: While not specific to "carrier bearings" in the traditional sense, drive unit bearings can, over time, develop noise or wear, potentially leading to a whirring or humming sound.
• Motor or inverter issues: Problems can arise with the electric motor itself or the inverter that controls it, leading to diminished performance or error messages. These are typically complex issues requiring specialized diagnostic equipment and service.

It's important to note that these are general considerations for electric drivetrains and not necessarily widespread endemic issues for the 2019 Tesla Model X. Tesla vehicles receive over-the-air software updates that can sometimes address performance or efficiency aspects related to the drive units.

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