Back to all

Tacky or Techie? The Tachometer.

June 21, 2020

There's a gauge that many vehicles have that says RPM on it.  And there are a lot of people who either don't pay any attention to it or don't even know what it is. Here's why it's a good gauge to know about.

It's called a tachometer, and that "RPM" label means it is measuring how many revolutions per minute (RPM) the engine is turning.  Automotive experts know that a vehicle's engine can be damaged if it turns too fast (revving too high) or too slowly ("lugging" the engine).

A tachometer (sometimes called a tach) is almost a "must-have" gauge for vehicles with a manual transmission; the driver has to manually change gears; the tach helps the driver know when revolutions are in the optimal range.

Some say you don't need a tachometer if you drive a vehicle with an automatic transmission. It's true that most drivers of automatics don't even look at it.  But there are times when paying attention to the tach can help you prevent an expensive repair.

Here's a good example.  Manufacturers now build many of their automatic transmission vehicles with shift paddles.  They let you shift gears without a clutch. That's manual shifting, and drivers need to know they're not revving the engine too high. That's where the tachometer comes in, since it shows you visually when you are in the red zone (RPM too high).

Here's another way the tach can help you: fuel economy. Generally speaking, the lower the RPM, the better the fuel economy. It's not good to go too low, of course, and the tachometer will help you find that spot of maximum efficiency.

You can also spot problems by paying attention to the tach.  When your vehicle stays in first gear longer than usual (higher reading on the tach), then the RPM dip lower than usual after shifting, it may be that your vehicle's transmission is skipping a gear.  Plus, if your vehicle's RPM go up but your speed doesn't, it could mean your transmission is slipping.  Either situation should be checked by a trained technician.

If your commute takes you down some long grades, you might like to put your vehicle in a lower gear to help slow down the car (and not burn up the brakes). Having a tachometer keeps tabs on when your engine is revving too high.

So, consider the tachometer a "bonus" gauge.  It's one more helpful assistant that can help you spot and prevent problems in your vehicle.

Tuffy Tire & Auto Service Center Lewis Center
210 Hornbeam Lane
Lewis Center, Ohio 43035
740-549-3332
http://www.tuffylewiscenter.com

More articles from Tuffy Lewis Center

A Not-So-Straight Story (Vehicle Pulls to One Side)

March 24, 2024

A vehicle should travel straight down a straight road with the steering wheel centered. But time and travel can take their toll and soon you may find your vehicle pulling to the left or right. Those are not good signs and should be taken care of fairly quickly. One thing that you should note is... More

Such a Little Part (Climate Control Resistor)

March 17, 2024

You expect your heater/air conditioner to work like it should. You have a control for temperature and one for fan speed. You even have a control for what vents the air comes out of. Don't be surprised one day if your blower fan develops a mind of its own and starts going crazy. Most of the ti... More

Things Aren't Always What They Seem

March 10, 2024

If you drive, you know at some point, something's going to go wrong with your vehicle. And sometimes, it's pretty easy to figure out what's wrong, like a flat tire. But sometimes your vehicle's symptoms can be really puzzling. One driver in Ohio was heading to work on a hot July day and noticed... More