2020 Toyota Highlander Transmission & Axle Gear Ratios

Transmission gear ratios

The 2020 Toyota Highlander comes with two primary powertrain options, each featuring a distinct automatic transmission. The 3.5L V6 engine is paired with an 8-speed automatic transmission, while the Hybrid model utilizes an electronically controlled continuously variable transmission (ECVT).

8-Speed Automatic Transmission (3.5L V6)

Electronically Controlled Continuously Variable Transmission (ECVT) (Hybrid)

The ECVT in the Highlander Hybrid operates differently from a traditional geared transmission. Instead of fixed gear ratios, it uses an electric motor and generator to provide seamless and continuously variable power delivery. The "ratios" are effectively infinite within its operating range, allowing the system to always find the optimal balance between efficiency and power.

Available axle ratios

The 2020 Toyota Highlander offers different final drive ratios depending on the powertrain and drivetrain (FWD or AWD). For the 3.5L V6, the final drive ratio is effectively the axle ratio, while for the Hybrid, it's the ratio after the ECVT to the wheels.

3.5L V6 Engine

Hybrid Models (ECVT)

Note: Toyota does not typically use specific "RPO codes" for axle ratios in the same way some American manufacturers do. The final drive ratio is inherent to the specific transmission/drivetrain setup.

How to identify your axle ratio

Identifying the axle ratio on a 2020 Toyota Highlander is not as straightforward as with some domestic trucks that provide RPO codes on a door-jamb sticker or a physical axle tag. For the Highlander, the axle ratio (or more accurately, the final drive ratio) is determined by the specific transmission and drivetrain configuration it came with from the factory.

• VIN Decoder: The most reliable way to confirm your vehicle's original specifications, including powertrain and drivetrain, is to use a Toyota VIN decoder or contact a Toyota dealership with your VIN. They can provide an accurate build sheet that will confirm your vehicle's exact configuration. You can often find free VIN decoders online that can provide basic information.
• Owner's Manual/Dealership: Your owner's manual might contain general specifications, or a Toyota dealership will be able to tell you the precise final drive ratio based on your VIN.

Towing vs MPG impact

Understanding the relationship between axle ratios, towing capacity, and fuel economy is crucial. Generally:

• Numerically Lower Axle Ratio (e.g., 3.003): This ratio means the engine doesn't have to rev as high to maintain a given road speed. This translates to better fuel economy, especially on the highway. However, it provides less mechanical leverage for starting from a stop or pulling heavy loads, thus reducing perceived "grunt" and towing capacity.
• Numerically Higher Axle Ratio (e.g., 4.605 - common in hybrids due to electric motor assistance): A higher ratio causes the engine to rev higher at a given road speed. While this might slightly decrease highway fuel economy (relative to a lower ratio in a non-hybrid), it significantly increases the mechanical advantage at the wheels, providing more torque for acceleration and especially for towing. In the case of the Highlander Hybrid, the electric motors provide instantaneous torque, allowing for a numerically higher "axle ratio" while still achieving excellent fuel economy.

The 2020 Toyota Highlander is designed with specific final drive ratios optimized for its intended use and powertrain. The V6 models offer a balanced approach, while the Hybrids leverage their electric motors for both efficiency and effective power delivery with a numerically higher final drive.

Common issues

The 2020 Toyota Highlander is generally known for its reliability. Issues specifically related to the differential or final drive components are not commonly reported as widespread problems. However, like any mechanical component, wear and tear can occur over time.

• Differential Whine: A persistent whining noise that changes with road speed and often becomes more noticeable during deceleration can indicate wear in the ring and pinion gears or differential bearings. This is more common in vehicles with higher mileage or those that have been subjected to consistent heavy towing without proper maintenance.
• Carrier Bearing Wear: The carrier bearings support the differential unit within the axle housing. Wear in these bearings can lead to humming or rumbling noises, which may also be accompanied by vibrations.
• Limited-Slip Clutch Wear (if applicable): While the Highlander typically uses an open differential (or electronically controlled AWD that simulates limited slip), if any aftermarket or specialized limited-slip differentials were installed, clutch wear could lead to chattering or clunking noises during turns.

Regular maintenance, including checking and changing differential fluid as recommended by Toyota, is crucial for extending the life of these components and preventing premature wear.

Find a driveline shop on Repairius.