Back to all

Tacky or Techie? The Tachometer.

March 28, 2021

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.

Charlie's Fast Lube Poplar Bluff
2020 N. Westwood Blvd
Poplar Bluff, Missouri 63901
573-686-5585

Need Service?

Request a Quote

More articles from Charlie's Fast Lube Poplar Bluff

Emergency! (Vehicle Emergency items)

March 9, 2025

"I never expected it could happen to me." Countless drivers have said that after they've had an emergency turn their lives upside down. So before that happens to you, let's thinking about planning ahead for an emergency with a few things you should keep in your vehicle. Road flares. If you've ev... More

It's (Not) Complicated (Engine Air Filter)

March 2, 2025

While many components of your vehicle are complex and composed of lots of mechanical and electrical parts, there's one that isn't complicated but still important. It's your engine air filter. (And, we should point out, the engine air filter isn't to be confused with the cabin air filter. The ca... More

Passing the Test (How to Prevent Emissions Test Failure)

February 23, 2025

Vehicle emission testing has become ubiquitous in North America and for a good reason. Clean air quality is important for the environment and all of us. Since vehicle emissions are among the main causes of air pollution, emission testing can alert you to problems in your vehicle than can be fix... More