Tachometer

[rosco5]

The tachometer in the Journey IP (and most all cars) takes up a lot of real estate but doesn't seem to serve a useful purpose. How do those-in-the-know use a tach? Can it help efficiency/mpg's? In short - what's this thing for anyway?

[RickC]

The tachometer in the Journey IP (and most all cars) takes up a lot of real estate but doesn't seem to serve a useful purpose. How do those-in-the-know use a tach? Can it help efficiency/mpg's? In short - what's this thing for anyway?

I'll agree that it's pretty useless in cars with a basic auto trans, but the Journey (along with lots of other new cars) have that auto-stick thing. So having the tach helps in driving when shifting manually.

[radon360]

The tachometer in the Journey IP (and most all cars) takes up a lot of real estate but doesn't seem to serve a useful purpose. How do those-in-the-know use a tach? Can it help efficiency/mpg's? In short - what's this thing for anyway?

It's lost a lot of its purpose with an automatic transmission, yet the proliferation of them on new cars would have you think otherwise. I think it's more of a marketing thing. The tach balances out the instrument cluster, implies the sense of performance...apply any "feel-good" reason you'd like.

Overreving the engine really isn't a problem any more. The electronic control for the transmission, coupled with the electronic throttle control (yes, the accelerator pedal is not connected to a throttle cable) basically won't let you do it.

Now, if you want to be a little more of a technical zealot, then you can find some use. If you have the 3.5L V6, then you have the six speed with the autostick. Given how quiet the engine noise happens to be in the passenger compartment, the tachometer is almost a necessity for knowing where to shift. Granted, the computer control won't let you do anything seriously bad for the transmission, but it's hard to guess where you want your shift points if you don't have much of anything to go by.

Similarly, you can monitor how the transmission is behaving. Things as to when the transmission shifts, or if the torque converter is locked up. "Why care?" you might ask. Well gear hunting and the torque converter unlocking is an indication that transmission maybe working harder than it should, such as when pulling a trailer or very hilly roads. This can lead to excessive heat in the transmission and premature breakdown of transmission fluid, potentially leading to a transmission failure later. If you observe the tach bouncing around a lot under such conditions, you can take actions, such as keeping the transmission out of overdrive to prevent such problems. Yes, your fuel economy may suffer a bit, but better than being left at the side of the road with a broken transmission.

So yes, the tachometer really doesn't have much purpose in life any more, but in a few particular technical situations, it can prove to be a handy diagnostic and indication tool of what is going on under the hood.