There are two types of Tire Pressure Monitor System, the Direct TPMS and the Indirect TPMS. In this article, we’ll be discussing the difference between both of these types of Tire Pressure Monitor System.

There are certain differences between the types of TPMS. They can be compared on various scales, including accuracy, cost, maintenance and installation. The Direct TPMS is more accurate and gives more concise data. The Indirect TPMS works with estimates on the air pressure of tires. The Direct TPMS is also more expensive than the Indirect TPMS.

The Direct TPMS can be complex to understand and install, it also requires a certain level of maintenance. This involves changing the batteries of the sensors at intervals which could also be expensive. The Indirect TPMS is a lot simpler to handle and install. Its maintenance also involves simply recalibrating the sensors after a tire change.

The Types of TPMS

There are two types of Tire Pressure Monitor Systems, the direct and the indirect. These two types have distinct differences which would be explained here. They are built differently and make use of different technologies to monitor the air pressure of a tire.

The Direct TPMS: This uses a sensor technology. It is built with sensors which are placed directly inside the tire. This makes it easier for it to come in contact with the parts of the tire and read its air pressure. It gives a very accurate reading of the tire’s air pressure. It reads and monitors the air pressure in real time, and it does this for each of the tires at the same time.

The Indirect TPMS: This TPMS type uses the ABS or Anti-lock Braking System. It basically piggybacks off it. The sensors are for wheel speed and are installed inside the ABS. The sensors read the rotation speed of the tires. Using this, it estimates the air pressure of the tire. It also applies the calculations from the difference in wheel rotations. It is a less accurate option but it is cheaper, so cost effective.

What Is a TPMS?

A Tire Pressure Monitoring System or TPMS is a safety device for vehicles. It is designed to monitor the air pressure inside a tire and send an alert to the driver when it drops or goes above the recommended tire air pressure levels.

This technology works by monitoring tire pressure, processing the measured data and alerting the drivers. The Direct TPMS monitors the air pressure using sensors in each tire while the indirect depends on the data from ABS. The system processes these data and then alerts the driver if there are any abnormalities.

Definition and Primary Function.

A Tire Pressure Monitoring System or TPMS can be defined as an electronic system designed and created to monitor the air pressure inside a vehicle's tires. This system is built with some form of alert to notify the driver when the tire’s air pressure is below or above the recommended level.

The primary function of a TPMS is to make sure the tires are inflated properly, have the correct air pressure. These things help with safety, manage fuel and make the usage more efficient and also protects the tire from wear and tear, improving lifespan.

Legal and Safety Reasons for TPMS Use

Legally, the use of a Tire Pressure Monitor System in some regions and countries are mandatory. They do this for safety reasons. The use of a TPMS can help keep the vehicle, driver and other road users safe. It is very helpful as tires in underinflated states can cause accidents. Tires in overinflated states can do the same too and even lead to a blowout.

Overview of How TPMS Contributes to Vehicle Safety and Fuel Efficiency

Absence of a TPMS in a vehicle can lead to poor management of fuel and rapid wear and tear on the tires. The use of a TPMS allows a driver to monitor the air pressure in their tires. This in turn helps know the exact condition of the tire at all times. It basically can serve as a maintenance feature for tires. Also, when a tire rotates properly it puts the fuel to efficient use.

What is Direct TPMS?

A Direct TPMS is one of the two types of Tire Pressure Monitor System. It functions and performs the task of monitoring the air pressure of a tire by using sensors inside each tire to measure the air pressure directly. This type of tire pressure monitor system uses a sensor to monitor the air pressure directly in the tires. Hence, the name direct TPMS. The sensors are placed in each of the tires of the vehicle. This type of TPMS sends alerts in real time about issues like low pressure or leaks. It also sends the tire air pressure data in real time too, making it very efficient. The alerts are also better because they are to specific tires. The direct TPMS uses a battery for the sensors that need to be replaced from time to time. This is the most preferred type of Tire Pressure Monitor System. That fact is due to its advantages over the indirect Tire Pressure Monitor System.

Explanation of How Direct TPMS Works:

Now, how do direct TPMS work? They make use of sensors to read the internal air pressure of a tire. The sensors are mounted inside the tire, on the valve stem of the tire or inside the wheel. This allows the sensor to measure the air pressure directly.

The data gotten from the sensor’s reading is then transmitted to the control unit of the vehicle. It does this using wireless technology for a seamless experience. Finally, an alert displays on the vehicle’s dashboard notifying the driver of a drop or increase in the air pressure.

Components Involved

There are certain components associated with a direct Tire Pressure Monitor System. They are Tire-mounted sensors, Sensor batteries, Control unit and dashboard display. All these components are important in a direct TPMS and all serve their purposes.

Advantages:

There are various advantages to the use of a Direct TPMS

For example, the high accuracy it has when measuring tire air pressure.

There’s also the real-time monitoring feature. This runs even when the vehicle isn’t moving. Also, the direct TPMS can cause gradual or sudden loss in air pressure.

Common Drawbacks:

As like every other technology or device, there are always limitations and drawbacks.

For a direct TPMS this involves the high cost for additional components.

The maintenance which requires a regular replacement of the sensor batteries.

It can also be very complex to install, especially when the tires or wheels of the vehicle are changed.

What is Indirect TPMS?

Indirect Tire Pressure Monitor System is the second type of TPMS. It estimates the air pressure in a tire by monitoring wheel speed using the vehicle’s Anti-lock Braking System (ABS) or Electronic Stability Control (ESC).

This type of TPMS uses the Anti-lock Braking System or ABS as a method to gain data on the vehicle’s tires. This is less accurate and works with estimates. The estimates are made based on the differences in tire rotations. The size of the tire and wear also affects the readings by this type of TPMS. The indirect TPMS measures the speed of the wheel and uses the data to detect any issues in the tires.

Explanation of How Indirect TPMS Works:

How it Works:

When a certain tire is underinflated, it rotates faster than it should. Properly inflated tires roll at a regular speed but this is different for underinflated tires due to a reduction in air pressure and circumference. The Indirect TPMS detects changes like this and sends an alert to the driver.

Integration with The Vehicle’s ABS/ESC System

Now, for an Indirect TPMS to work properly, the sensors have to be properly integrated into the ABS or the ESC system of the vehicle.

Advantages:

The advantages of an Indirect TPMS are lower cost.

It is a cheaper alternative than the direct TPMs and also doesn’t require additional sensors. The maintenance of the indirect TPMS is way simpler and doesn’t need batteries. Lastly, It is integrated into an already existing ABS or ESC system.

Limitations: 

There are also limitations and slight disadvantages to the use of Indirect TPMs. Especially when compared to its rival, the direct TPMS. The Indirect TPMS is less accurate than the Direct TPMS.

It also requires a manual recalibration after the tires are changed or after every rotation. Also, it may not be well equipped to detect loss of air pressure in the tire under certain conditions. An example is when all the tires are underinflated.

Key Differences Between Direct and Indirect TPMS

There are certain differences between the Direct and Indirect TPMS. They key ones are:

Accuracy:

The direct TPMS measures the air pressure accurately and provides a precise reading. The indirect TPMS on the other hand relies on estimates based on the rotation of the tires.

Cost:

The Direct TPMS is also more expensive than the Indirect TPMS due to the need for additional sensors. The Indirect TPMS is cheaper and cost friendly since it makes use of tools already on the vehicle. You can review products here and compare prices.

Maintenance:

For the Direct TPMS, the sensors and batteries might need to be replaced regularly. The Indirect TPMS on the other hand needs to be recalibrated after the tires are changed or after a rotation.

Real-Time Data:

In this aspect, the Direct TPMS sends real-time information to the driver even when the vehicle isn’t moving. The Indirect TPMS has to rely on movement of the wheels and also waits for the data to be interpreted.

Compatibility:

Lastly, compatibility. The Direct TPMS can work with most vehicles. The indirect TPMS might face certain issues with aftermarket tires or ones with irregular sizes.

Pros and Cons Comparison Table

Visual representation comparing Direct TPMS and Indirect TPMS side-by-side:

Which System is Right for You?

When deciding on a TPMS system to use, you must consider certain things.

Factors to Consider:

For budget, the Indirect TPMS is a better option if the driver is on a low budget.

The vehicle type is also considered, and the Direct TPMS works better for luxury and high-performance vehicles.

If the goal is minimal maintenance, the Indirect TPMs is the right option.

And finally, for accuracy and real time readings, the Direct TPMs is the best option.

Recommendations for Specific Use Cases

For luxury and newer models of vehicles, the Direct TPMs is a better option for more accuracy and real-time data.

For fleets and older models, the Indirect TPMS works better as it is cheaper and simple to use.

Conclusion

When deciding on the right TPMS to use, the budget and vehicle type are important factors to look at. The Direct TPMs work a lot better but are expensive and not easy to maintain. The Indirect TPMS is much cheaper but less accurate. Getting the best TPMS for your vehicle helps with safety, fuel efficiency and increases the lifespan of your tires. You should always get authentic products and can check out this page, you can learn more about TPMS here.