There’s no doubt about it; if you want to get the best performance from almost any vehicle, a tachometer is a must. A tachometer will help you maximize everything from acceleration and top speed to fuel efficiency. But what is a tachometer, and how does it work?
What is a Tachometer?
A tachometer is an instrument used to measure the rotation of a disc or shaft. This measurement gives a read-out in revolutions per minute (RPM).
What are Tachometers used for?
All internal combustion engines have an optimum engine speed for peak performance. When a motor has a tachometer fitted, the tachometer measures the speed of the crankshaft. Knowing this speed allows the operator to keep the engine revving at the optimum speed.
What’s the Difference Between a Tachometer and a Speedometer?
A tachometer gives the speed of the engine. A speedometer gives the overall speed of the vehicle.
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The tachometers we have reviewed in this article
This tachometer with its brushed aluminum face screams ‘old school.’ It will sit in your muscle car or hot rod dash, looking as if it’s been there forever. Thanks to the Auto Meter’s innovative electronics, it works in all sorts of vehicles, from a retro big block rebuild to high-performance racing ignitions.
The gauge is 3” in diameter, features a white LED through the dial light, and has an 8,000-rpm limit. This tachometer may be one of the more expensive in our lineup, but you are paying for quality and versatility. Compatible with two to eight-cylinder engines, points, or electronic ignitions, the tacho will work with the electrical system in almost any street or race car.
Automotive innovators for over 100 years Bosch have only recently launched into the gauge market with their Actron range. Rather than an in-dashboard replacement, this 2⅝” tachometer is a bolt-on option. The black dial with white numbering and red detailing give the gauge an authentic after-market performance look.
Increments run from 0-8000-rpm, and a great feature is the adjustable redline pointer, which allows the user to dial in their rev limit. The Actron is compatible with four, six, and eight-cylinder engines and most ignition systems except for magnetos.
This 3¾” Autogage offers excellent bang for buck. And its diameter and pronounced bezel shoulder wouldn’t look out of place sunk into the dash. It’s lightweight, and the supplied mounting bracket means column or dash mounting isn’t an issue.
The face features incandescent lighting around the perimeter, which gives the tachometer a retro glow while still being easy to read. When it comes to compatibility, the Autogage will work with four to eight-cylinder engines with either points, electronic, or most racing ignitions.
This full-size clock has integrated mounting hardware on the base, making it a dash or column mount only. With its silver bezel, white face, and fluorescent needle, the 233090 is designed to stand out.
The Autogage works with engines configured with four to eight cylinders and two-four ignition pulses per revolution. For use with 12v or 16v systems, the gauge will work with mechanical points, electronic, or race ignitions.
If you have a hard revving engine that needs to remain in its powerband for max results, then this gauge is the one for you. A 10,000-rpm incandescent lit clock face gives a clear read-out, and the Autogage also features a programmable, high visibility shift light so you know when it’s time to grab that shift knob.
Here is another offering from the Bosch Actron line. But this time, the tacho features a white face with a chrome bezel. Weighing in at less than 1-lb, the gauge with its supplied mounting hardware is designed for dash or column mounting.
If you have the room in your car or truck, its chrome bezel lip means it can also be in-dash mounted. An air core motor drives the 0-8000-rpm dial, and the gauge features an adjustable redline pointer. Most OEM ignition systems are compatible (except magnetos) and function with four to eight-cylinder engines.
The Sport II benefits from high accuracy with fast needle sweep. As with the entire Actron collection, there is a full range of accessories available. These range from installation kits to gauge pods.
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You can install this tachometer in almost any vehicle. With its 11,000-rpm dial, race-tech looks, and features, it’s most likely going to find a home in more modern cars and trucks.
With the ignition off, the smoked screen appears blank, but the clock jumps to life once on. The neon blue numbers and red LED needle make it easily visible in daylight, and the tacho features a programmable shift-light.
You will also find a visual and audible warning function that tells you if maximum revs are being exceeded on this model. The gauge is a dash or column mount only and features a satin black clock mount and hardware. The tachometer is compatible with 12v electrical systems and multi-cylinder engines.
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This large diameter tachometer has a neat satin black casing and trim. The mounting hardware is designed for dash or column mounting only, but GlowShift also makes an in-dash version.
Thanks to the gauge’s LED technology, you can choose from seven solid colors and two-color cycle modes to either contrast or match your OEM dash lights. The GlowShift features an adjustable in-clock shift light, and the illuminated needle sweeps smoothly from 0-10,000-rpm.
Although compatible with most ignition systems and cylinder configurations, this tachometer is for use with gasoline engines only. With the ignition turned off, the dial goes into stealth mode, and there’s also a dimmer function for driving at night.
When Auto Meter says ‘Monster,’ they aren’t joking! The Autogage 233904 is a whopping 5-inch in diameter, while the side-mounted shift light adds to its formidable presence. The shift-light adjuster control is located on a bracket on the clock face, and with its white on black dial, this tachometer looks all business.
With an air core motor at its center, the 233904 is not only accurate but also fast, with a needle response that goes from zero to its limit in 333 milliseconds! This model covers four to eight-cylinder engines, points, electronic, and race ignitions. Judging from the included mounting bracket, it’s suitable for on-dash or column mount only.
This retro line Bosch may look like a factory-fitted part from the 1950s, but inside, it’s high tech all the way. The air core motor gives accurate, fast readings from zero right up to its 8000-rpm limit.
At first glance, this tachometer’s chrome housing with its white on black markings, and increment display in 10’s, appears more like a fuel or amp gauge. With its green backlight, though, its retro-look credentials are impeccable.
One of the most flexible tachometers in our review, the Bosch can be set to work with one, two, four, six, eight, ten-cylinder engines and most ignition systems.
It’s possible to remove the chrome cup so the tacho can be in-dash mounted. This tachometer also comes with two brackets for on-dash or column mounting but does not come pre-wired. This would for sure match an aftermarket steering wheel great as well!
Who says tachometers are for two and four wheels only? This purposeful-looking tachometer is made for marine use and is compatible with four, six, and eight-cylinder, and V6 engines.
Suitable for 12v and 16v electrical systems, the bezel is sealed to protect from water ingress. A carbon fiber face and UV-resistant paint on the needle also means the tachometer will remain in ship-shape condition.
The gauge is designed to mount in-dash and comes with a bulb and socket assembly with red and green bulb covers. The mounting hardware is corrosion-resistant.
This simple, no-nonsense tachometer is designed for in-dash fitment only. What you see is what you get, and the 5-ins diameter, white face, and fluorescent orange needle make it super easy to read.
The Auto Meter gets an air core motor for accuracy, and its traditional feel continues thanks to incandescent perimeter lighting. Compatible with almost every street and race car electrical system, this tachometer is excellent for four to eight-cylinder engines with two to four pulse ignition signals.
This Chesapeake tachometer with its black and blue graphics on a white face looks super sharp and easy-to-read. The numbers are incremented in 10’s, and the gauge reads from 0-60 (6000-rpm).
The plastic bezel is sealed and comes with an attractive stainless steel outer rim. This model is designed for gasoline-powered inboard or stern-driven engines, although other variants are available.
Apart from looking classy and fully functional, the Chesapeake’s stand-out feature is its digital seven-figure LCD hour-meter. This function tells you how many hours a boat engine has run, which is essential for service intervals or overhauls.
If you’re going to bolt this tachometer to your dash, you’ll need a muscle car with a big block engine at the very least. Weighing at 2-lbs, the 5” Sunpro is the heaviest gauge in our lineup, and the chrome metal casing will give it a real presence in the cockpit.
The black and white dial graphics and red indicator needle give the gauge a classic look. The large shift light can be placed at any position around the bezel.
The gauge can be set to work with one to ten-cylinder engines. The air core motor is vibration-proof, and the backlit dial makes it easy-to-read. If you like tachometers big, bold, and drag strip ready, the Sunpro fits the bill.
Do I need a tachometer?
No. But if you want to get the most power or best gas mileage out of your engine, then it’s a Yes.
How Does a Tachometer Work?
A tachometer measures the revolutions of the crankshaft, either mechanically or electronically.
What Does RPM Mean?
Revolutions per Minute
Adding a tachometer to your vehicle gives it a custom look and provides a needed and practical function. Being able to monitor accurate engine speed is the best way to maximize an engine’s potential.
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