Most late-model vehicles today come with a digital speedometer that accurately measures how fast you’re going. Better still, you may want to invest in aftermarket options like GPS speedometers. But how do they work, and are they better than standard ones?
A GPS speedometer measures a vehicle's speed by calculating the changes in its geographic position. It relies on GPS satellites to work correctly, which means driving in tunnels or covered routes can affect its operation. Still, GPS speedometers are more accurate than conventional ones, so it could be worthwhile for some car owners.
Check out the rest of this article to learn how GPS speedometers work and their pros and cons.
What Is a GPS Speedometer, and How Does It Work?
A GPS speedometer is exactly what it sounds like. It's a speedometer with GPS or Global Positioning System capabilities. That means the speedometer can send and receive signals to communicate with satellites in space.
What the name doesn’t tell you is that the GPS capability isn’t only used to locate your vehicle but also to calculate how fast your car moves.
To put that into perspective, let’s take a quick look at what conventional speedometers do.
What Is a Conventional Speedometer, and How Does It Work?
Cars and other motor vehicles have speedometers to tell the driver how fast they’re going. That way, they can maintain vehicle control and stay within legal speed limits.
Most modern cars use electronic speedometers paired with either digital or analogue displays. The display will adjust in real-time to let you know how fast the vehicle is going and whether it's speeding up or slowing down.
Older, less common mechanical speedometers also do the same, but you won't find them in many vehicles on today's roads.
Although mechanical and electronic speedometers have different components, they work in similar ways. They gauge how fast your car is moving by measuring the transmission system’s output speed.
How Does a GPS Speedometer Work?
GPS speedometers work in a very different way compared to the conventional ones described above. Instead of measuring data from within the car itself (i.e., at the transmission system), it measures the change in your vehicle’s geographic position at quick intervals.
Speed is a function of distance and time. So, what GPS satellites do is use a vehicle’s position changes and time lapsed to calculate how fast your vehicle is moving in real time. Then, it'll continuously send that data to the speedometer inside the car.
All of that is possible and highly accurate because GPS tracking capabilities are accurate down to 5 meters. In other words, it has no problems locating your car from space, let alone tracking its movements as you drive down the road.
What Components Does a GPS Speedometer Use?
Earlier, you read how conventional speedometers rely on several components to function correctly. Even in a more straightforward electronic speedometer, sensors and wires are involved in the process.
GPS speedometers, however, are straightforward.
A GPS speedometer consists of a heads-up display unit and typically a USB power cable. Those two things are all that’s needed, as every component is built neatly into the display unit.
In other words, a GPS speedometer is ready-to-use straight out of the box. You can also use it on any other moving vehicle if you'd like, such as all-terrain vehicles (ATVs), motorcycles, trucks, and more.
What Are the Benefits of GPS Speedometers?
It's easy to see how a speedometer with GPS can benefit you in several ways. For example:
- Higher accuracy: Remember that conventional speedometers calculate your vehicle’s speed based on the transmission’s output. While that’s still accurate, GPS speedometers are even more accurate because they measure the changes in your car’s geographic position.
- Unaffected by car modifications: Measuring a car’s speed the way conventional speedometers do has some drawbacks. For example, vehicles with modified suspensions and wheels can cause the speedometer to become inaccurate. However, GPS speedometers remain accurate and are unaffected no matter how a car is modified.
- Prevents fines: GPS speedometers are also better at helping you avoid speeding tickets. That’s partially due to its higher accuracy, as described above. Besides that, GPS systems can also help you track local speed limits in different areas. As such, some systems can also warn you when speed limits change based on where you’re driving.
The above benefits offer you many reasons to invest in a GPS speedometer. But be sure to consider the drawbacks that come with such a device.
Are There Any Drawbacks to GPS Speedometers?
Whether you’re buying a GPS with speedometer capabilities or a speedometer that comes with GPS, there are some significant drawbacks you must be aware of.
Consider these factors before deciding to invest in a GPS speedometer:
- Added cost: The first drawback is the additional cost of investing in a GPS speedometer. Remember that all motor vehicles come with a conventional speedometer as a standard feature, so upgrading to a GPS model will cost you extra.
- Signal Interruptions: A GPS speedometer can only work when it continuously sends and receives signals from the satellites above. Although they’re rare, signal disruptions can happen. When they do, your speedometer won’t work.
- Tunnels and covered routes: Signal interruptions like the ones described above are unpredictable. However, there are GPS signal outages that are entirely predictable. For example, your speedometer will lose its signal when driving into tunnels or other covered routes. That can be quite worrying if your daily routes involve those kinds of structures.
The drawbacks mentioned above aren't necessarily deal breakers for GPS speedometers, but it's wise to consider them before investing in one.
Bottom Line: Are GPS Speedometers Any Good?
All things considered, GPS speedometers can be useful for some vehicles where the standard speedometer is not as accurate as you want it to be.
However, electronic speedometers in today’s cars are already as accurate as anyone needs them to be.
So, while a GPS speedometer might be a nice-to-have, it’s certainly not a need-to-have for most car owners.
Stay tuned to the CarpartAU Blog to learn more about different aftermarket accessories and devices. You'll learn which ones can help you drive better, and which might not be worth the investment.
By Ray Hasbollah