Back to all

Tacky or Techie? The Tachometer.

November 10, 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.

Tire Warehouse Depot
250 N. Lapeer Rd.
Lake Orion, Michigan 48362
248-929-0699

Need Service?

Request a Quote

More articles from Tire Warehouse Depot

Grinding, Jerking and Slipping

July 26, 2026

Gone are the early days of driving when people had to manually shift gears in their vehicles. Now, though, we are spoiled by automatic transmissions that seem like theyll go forever. Like everything mechanical, automatic transmissions can develop problems. Signs trouble is brewing sometimes s... More

Why is My Vehicle Overheating?

July 19, 2026

When it comes to your vehicle overheating, the signs can be loud and clear when you have a problem. You may see a thermometer-shaped warning light come on or a temperature gauge whose needle is pointing in the red zone. When either of those happen, its important to take quick action to avoid se... More

Control Arms: Small Part, Big Impact

July 12, 2026

Heres one part of your vehicle you may never have heard of: the control arm. Its the part that connects the wheel hub and steering knuckle to your vehicles frame. What it does is lets your wheel move up and down while keeping it aligned with your vehicle. Most control arms have things called ... More