Complete Guide to GPS Speedometers

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Complete Guide to GPS Speedometers

GPS first hit the scene in the 1960s, and just a few short decades later, the technology is everywhere, from smartphones to fitness trackers to vehicle dashboards. GPS does more for drivers than just giving point-to-point directions and traffic alerts. One of its lesser known uses in the car is gauging driving speed. Before switching from a traditional to a GPS speedometer, vehicle owners need to know how they work, how they stack up against standard speedometers, and how to install them.


How GPS speedometers work

Often referred to as positional speedometers, GPS speedometers calculate speed based on the distance an object moves in a specific amount of time. These devices consider the Doppler shift when determining speed. GPS speedometers run continuous calculations and provide regular updates so drivers have the most accurate information possible at any given moment.

Beyond real-time speed updates

Individuals typically use GPS speedometers just to gauge and read speeds. Companies, on the other hand, often integrate fleet management software to determine employees' speeds on the job. Employers analyse speeds provided by the software and then flag employees who exceed the limits. Although companies do not need fleet management software to use GPS speedometers, many enjoy the safety benefits the software provides.


Traditional vs. GPS speedometers

The primary difference is that GPS speedometers tend to be more accurate than traditional speedometers. Various factors impact a traditional speedometer's readings. For example, variations in wheel size influence the readings. Tyre pressure, temperature changes, tread wear, and the type of tyres used all impact wheel size, making it easy for traditional speedometers to provide the wrong readings. In fact, having a wheel and tyre combination that is different from the original factory setup impacts the speed reading on traditional speedometer displays.

In addition, manufacturers often calibrate traditional speedometers to give a speed reading that is higher than the actual speed. This limits their liability since they do not have to worry about readings that are too low, which might result in speeding tickets for drivers. As a result, many people drive slower than they think they are with traditional speedometers.


Wheel size does not impact the readings of GPS speedometers. Under good conditions, they are accurate within 0.2 kmh. Devices maintain this accuracy as long as they have access to GPS satellites. Drivers loose access when passing through tunnels and other areas that prevent the antenna from connecting with satellites. Some drivers choose to use a combination of standard and GPS speedometers in order to get total coverage regardless of satellite connection. This is typically not necessary for the average driver since there are very few areas where GPS antennas do not have access to satellites.


Installing speedometers

Many motorists are afraid of installing GPS speedometers. They assume these devices require a great deal of wiring, but that is not the case. Some GPS speedometers simply require connecting a few wires and placing the antenna on the outside of the vehicle. Other units do not require any wiring at all. Users simply plug the GPS speedometer into a 12V charger and mount the device on the dashboard.

Antenna placement

Drivers must pay attention to the GPS antenna placement. The antenna must have a clear view of the sky to get the best signal possible. If it does not have a clear view, the GPS device cannot provide accurate readings.


Drivers must calibrate standard speedometers based on wheel size and other factors so they work properly. Since GPS devices are positional, they do not require calibration. Drivers simply install the device and start using it. This makes the installation process much faster and easier for GPS speedometers.


Additional features

Many GPS speedometers are more than speed readers. Some include oil pressure gauges, water temperature gauges, and programmable fuel pressure and lever gauges. Some also include volt gauges and odometers. Some odometers simply display the vehicle's mileage, while others split into resettable trips. Speed alerts are also popular on these devices to help drivers avoid getting tickets.


How to buy GPS speedometers on eBay

It is easy to swap a standard speedometer with a GPS speedometer by shopping on eBay. Use the search box located on any page to search for the type of speedometer that you want. Look through the list of new and used GPS speedometers that match your search criteria, examine their various features, and make your decision. Make sure that you review the seller's shipping and return policies. Once you receive the speedometer, follow the installation instructions, and use it to more accurately gauge your speed.

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