Another subtle but significant change for the Model 3 and Model Y Standard trims has been discovered in the owner’s manuals for update 2025.38, and this one directly impacts the data drivers see on their screens, as well as safety warnings.
The new cut and added text in the manuals confirms that the new, more affordable models will no longer use the standard “direct” Tire Pressure Monitoring System (TPMS). Instead, Tesla will rely on an “indirect” system to notify drivers when their tires are low or critically low on air pressure.
For the owner, the difference is a simple warning of low tire pressure, instead of an accurately displayed reading. You will no longer be able to see the specific, real-time pressure (PSI) of each individual tire. While the car will still warn you if a tire is significantly under-inflated, the convenient on-screen data display is gone. This is a deliberate, engineering-driven decision to reduce cost, and it appears to be fully compliant with safety regulations.
Direct TPMS: Premium Feature
The system that most Tesla owners are familiar with is Direct TPMS. This is a hardware-based solution that places small, battery-powered Bluetooth sensors inside each wheel. These sensors directly measure the air pressure and temperature of each tire, and wirelessly transmit that data to the vehicle computer.
That’s the number that displays on your touchscreen in the Controls > Service menu, and enables you to proactively monitor tire health and pressure, and notice small pressure changes before they become a larger issue.
Indirect TPMS: Standard Solution
The new Standard trims will instead use Indirect TPMS, a rather clever, software-based system that requires no extra hardware in the wheels. Instead of directly measuring air pressure, this system uses the car’s existing Anti-lock Brake System (ABS) wheel speed sensors.
The logic is fairly simple: an underinflated tire has a slightly smaller diameter than a correctly inflated one, causing it to rotate at a slightly faster speed to cover the same distance. The Indirect TPMS constantly monitors the rotational speed of all four wheels. If it detects one wheel spinning consistently faster than the others, it infers that the tire is under-inflated and triggers a warning to the driver. However, it doesn’t actually know the tire pressure, just that one wheel has less pressure than the other.
Limited Support for non-OEM Wheels & Tires
Since this system relies on precise knowledge of the correct specifications for Tesla’s OEM tires, the indirect TPMS system may not function correctly if you replace the wheels or tires with sizes different from the OEM specifications. That also means that it will require recalibration when your tires are sufficiently worn down.
Calibrating Tire Pressure
This calibration procedure requires all four tires to be filled to their recommended cold pressure. After that, going to Controls > Service > Tire Pressure > Calibrate will enable you to begin the calibration procedure.
Driving over 15 mph (25 km/h) initiates the process, and maintaining stable speeds will help speed up the calibration procedure. The entire process requires about 20 minutes of driving to complete.
Tesla recommends a full recalibration every time you add or remove air from the tires, and notes that non-factory-installed tires, snow tires, or non-standard sizes may result in inaccurate calibrations.
Is This Legal?
The key to understanding this change lies in the regulations. In North America, vehicle safety standards (specifically the US TREAD Act) mandate that all new cars must have a system that alerts the driver when a tire is significantly under-inflated (usually by 25% or more). This alert is the familiar warning light on the dashboard.
However, the law does not require the vehicle to display the specific pressure value of each and every tire. The data-rich display provided by a Direct TPMS is a “nice-to-have” convenience and data feature, not one that is legally mandated. An Indirect TPMS, which only provides a warning, is compliant with regulations and is often used by many manufacturers in cheaper vehicles.
By switching to an Indirect system for its entry-level models, Tesla is making another compromise. It eliminates the cost and complexity of four battery-powered sensors per vehicle, reducing the vehicle’s cost while still alerting users to low tire pressures.
For new Standard trim owners, this means reverting to the old-fashioned method of checking tires: using a manual pressure gauge.
