Back to all

Tacky or Techie? The Tachometer.

October 20, 2019

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 Anna
1215 East Vienna St.
Anna, Illinois 62906
618-833-4999

Need Service?

Request a Quote

More articles from Charlie's Fast Lube Anna

Don't Neglect Your Spare (Spare Tire Care)

June 29, 2025

If you've ever had a flat tire, then you know welcome it is to have a spare tire that is properly inflated, in good shape and easy to get to. Problem is many of us don't even give our spare tire (if we even have one) a second thought. If you have an SUV or truck with a spare, it may be mounted o... More

Oil Times are a-Changin' (Oil Change Synthetic)

June 23, 2025

When it comes to oil changes, things are really changing. Most newer vehicles require synthetic oil, and while it costs more than conventional oil, it doesn't need to be changed as often. When conventional oil was the only game in town, you changed your oil every 3,000 miles/5,000 km. But as tec... More

When Your Air Bag Light Comes On (Illuminated Air Bag Light)

June 16, 2025

There are some dashboard lights you should pay more attention to than others. One is the air bag light. If it's on and your vehicle is in an accident, your air bags probably won't do their job. Automakers began installing air bags in the late 1990's since they were mandatory in the United State... More