Complete Guide to Tachometers

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Complete Guide to Tachometers

Perceptive drivers understand the value of monitoring their vehicles' performance through measures such as temperature gauges, speedometers, and tachometers. In the past, tachometers appeared only in top of the line sports cars and high-performance vehicles, so driving enthusiasts chose to install tachometers on their vehicles.

Although modern vehicles feature computer systems to observe the engine, tachometers still provide important information to help drivers keep track of engine performance. When shopping for a tachometer, consumers should understand the use for them as well as the different types available.


Purpose of tachometers

Tachometers measure the engine's number of revolutions per minute, also referred to as RPM. In cars with manual transmissions, a tachometer lets the driver know when the engine is ready to shift gears so it is not pushed beyond its limit, or redline. This is useful for race car drivers who want to maximise their performance on the track, or for driving up and down inclines when drivers need to keep the vehicle in low gears but do not want to damage the engine.


Types of tachometers

Engineers classify tachometers according to the way they display information and how they collect data from the engine. Understanding these classifications helps drivers choose the device that best fits their vehicle and driving habits.


Analogue tachometers have a face structure with a needle and dial that looks and functions like a speedometer. The dial moves around the face in response to the engine, letting the driver know the RPM. These classic style tachometers do not store readings or perform computations to help drivers track patterns in their driving habits or the engine's performance, but some have a light indicating the proper time to shift.


Digital tachometers have either an LED or LCD screen that displays the RPM. These tachometers typically have the ability to store information and gather statistics for the driver. For this reason, race car drivers often use digital tachometers in their cars to look for patterns in engine function, driving techniques, and time on the track.

Contact and non-contact

Contact tachometers attach directly to the engine and must stay in contact with the motor in order to collect information to send to the display. Non-contact tachometers use a laser or infrared light to gather data from the engine, and offer advantages such as the ability to measure hard to reach places and portability.


Choosing a tachometer

When choosing a tachometer, drivers must first consider how they plan to use it, as they only need a gauge that measures what the engine produces. For example, if the engine's redline is 5,000 RPM, the driver does not need a tachometer that measures up to 14,000 RPM. The car does not have a chance to reach the top number because the computer system shuts the engine off before it has a chance to experience damage from excessive RPM levels. Secondary considerations include where a consumer wants to install the tachometer on the dash and how it looks with the existing gauges.

Tachometer placement

In order to use a tachometer, the driver must be able to read it easily while driving. For this reason, most tachometers fit within the existing dash panel or rest on top it, making it important for drivers to ensure it does not obstruct their line of sight. At the same time, if the tachometer is too small, drivers cannot read it and gather the necessary information while on the road.

Cosmetic concerns

Drivers have the option of purchasing an individual tachometer or one that is part of a set with a speedometer. Manufacturers produce tachometers with a variety of face colours to complement the car's interior or enhance readability. In most cases, this is a matter of personal preference, and drives can select the gauges that look best in their vehicles.


How to buy a tachometer on eBay

When you are ready to install a tachometer in your vehicle, you can find an assortment of gauges on eBay. To find them, type the word "tachometer" in the search box on any eBay page, or search for a specific tachometer by using the manufacturer's name and model number. As you look through the available listings read the descriptions carefully, paying attention to details such as the device's specifications so you can find a tachometer compatible with your vehicle. Some sellers may also provide an instruction manual to help with the installation of the tachometer into your vehicle.

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