What is a Speedometer in a Car?

Evolution of the Speedometer

Did you know that the speedometer was invented as early as the 19th century? Yes. Charles Babbage and Josip Belušić developed the building blocks for the speedometer technology - following which Belušić created the first speedometer in 1888. Another milestone was reached in 1902 when German engineer Otto Schulze patented the modern speedometer. By 1910, it had become common practice to install speedometers in cars. In more recent years, we have observed the transition of the vehicle speedometer from analogue to digital. This has come in tandem with the implementation of other cutting-edge technologies in four-wheelers.

 

Types of Speedometers

As mentioned in the previous section, car speedometers have evolved from analogue to digital over the past decade. In this section, we will discuss both types of speedometers in detail.

 

Analogue Speedometer

The analogue speedometer has a mechanical functioning. A needle on a dial displays the speed, usually from 0-220 km/hr, based on the acceleration of the car. The needle is connected via a cable to the vehicle’s driveshaft. The drive shaft is connected to the wheels. As the driveshaft spins, the cable moves. This movement causes the magnet inside the speed cup to rotate at the same speed as the car’s tyres. A hairspring reads the magnet’s rotational speed and displays it on the car speedometer dial.

 

Digital Speedometer

These types of speedometers are generally used in modern cars. They don’t function mechanically like their analogue counterparts. Instead, they employ sensors and chips. In cars fitted with a digital speedometer, magnets and magnetic sensors interact with one another to produce an electric impulse in the circuit. These inputs are converted to speed and displayed on the car’s LED digital display. Since this system keeps count of the number of wheel revolutions, it also accurately displays odometer readings.

 

Digital vs Analogue Speedometers

Below is a table clearly showing the differences between digital and analogue speedometers against multiple parameters.

Parameter	Digital Speedometers	Manual Speedometers
Accuracy	Provide very accurate speed readings. Hence, ideal for drivers seeking accurate speed data.	Slightly less accurate in comparison with their digital equivalents. However, the error is within acceptable limits.
Functionality	Provide more information than just speed. Other info include trip details, fuel efficiency and kms to next fuel refill.	Typically displays only vehicle speeds. They exclude vehicle trips, performance and other details.
Power Requirement	They require power to function. Thus, these speedometers are liable to electrical failures.	Since they lack electronic parts, they are more durable and less likely to malfunction.
Visibility	Since the LED screen is lit, visibility is generally never an issue, regardless of the time of day or weather.	Visibility is generally decent, except at night. Although backlights are usually available for nighttime visibility, viewing is not as clear as in digital speedometers.
Price	They generally cost more and are more expensive to repair.	Typically, they are more affordable and cost less to repair.

 

Importance of a Speedometer for Safe Driving

Here are some ways a vehicle speedometer contributes to safe driving.

1. Legal Compliance: Being aware of the speed at which you drive will aid you in sticking to locally and nationally imposed speed limits.

 

2. Safe Driving: A speedometer helps you identify if you are driving at safe speeds. You can assess the ideal speed based on road conditions and the traffic around you.

 

3. Fuel Efficiency: If you are looking to maximise fuel efficiency, you can do so by making sure you drive at a constant speed. A speedometer can help you do this by displaying your current speed.

 

4. Responsible Driving: With the speedometer providing direct feedback to drivers regarding their driving behaviour, it is likely to keep drivers accountable while driving.

 

Additional Features on Modern Speedometers

Modern digital speedometers come with some additional features which include the following.

• Multiple Units: Some modern digital speedometers include the option to switch between mph and kmph.

• GPS Integration: Some modern speedometers incorporate the latest GPS technology to provide accurate speed readings and navigation.

• Speed Limit Indicator: In recent times, speedometers also emit a sound to indicate if you are driving beyond a high speed limit.

• Customisable Settings: Modern digital speedometers usually allow you to customise the brightness, layout, and colour scheme based on your preference.

 

Tips for Using Your Speedometer Effectively

Here are some tips on how to read a speedometer and how to use it effectively.

1. Regular Glance: Make it a habit to regularly glance at the speedometer to stay aware of your current speed.

 

2. Speed Limits: Pay attention to posted speed limits and adjust your speed accordingly using the speedometer as a guide.

 

3. Maintain Consistency: Use the speedometer to maintain a consistent speed, contributing to safer and more efficient driving.

 

4. Utilise Additional Features: If your speedometer has additional features like GPS integration or speed limit indicators, take advantage of them to enhance your driving experience.

 

5. Adapt to Road Conditions: Use the speedometer to adapt your speed to changing road conditions such as curves, hills, or adverse weather.

 

Speedometers and Vehicle Safety

The speedometer of a car measures how fast or slow you are driving and hence serves as an essential aid for safe driving. Another necessary safety feature your car requires is Car Insurance. In fact, as per the Motor Vehicles Act, it is illegal to drive without at least Third-Party Insurance. That being said, Third-Party Insurance only covers injury, death and property damage to a third party. That is why we recommend buying a Shriram Comprehensive Car Insurance policy. With this policy, you will not only receive third-party-related coverages but also coverage for damages to your own vehicle.

 

FAQs

In this section, we provide answers to frequently asked questions regarding car speedometers.

1. What is a speedometer used for?

A speedometer is a device that detects speed in vehicles. Some speedometers are coupled with an odometer that measures the distance travelled.

 

2. How accurate are speedometers?

Vehicle speedometers are generally accurate. However, electrical and mechanical issues can cause discrepancies in the reading. To offset this, we suggest regular maintenance and calibration of your car’s speedometer.

 

3. How are speedometers calibrated?

Speedometers are generally calibrated by trying to match the vehicle's speed. A trained mechanic usually calibrates them.

 

4. Are car speedometers repairable?

Yes, car speedometers can usually be repaired. The fix will vary depending on the type of repair. If your speedometer is malfunctioning, we recommend receiving assistance from a professional mechanic.