How come our cars don't come with a tachometer

[asaulo1]

I was just wondering why that is? I am always curios as to what the ICE is doing, rev wise? I know that for the most part, you can't really over rev it (is that really true?) since the Elec. motor kicks in to assist but I still would like to know like what rpm's the ICE is as like let's say when cruising down the freeway..... any one know?

[qbee42]

No tach since you don't have any direct control: you can't shift, can't over rev, can't even control when the ICE runs.

Tom

[ScottY]

Some of us use CAN-View to see the ICE RPM among other things...

<div class='quotetop'>QUOTE(qbee42 @ May 5 2006, 07:10 PM) [snapback]250515[/snapback]</div>

No tach since you don't have any direct control: you can't shift, can't over rev, can't even control when the ICE runs.

Tom
[/b]

Actually, we do have control over ICE rev, the "gas" pedal.

[NuShrike]

<div class='quotetop'>QUOTE(ScottY @ May 5 2006, 04:14 PM) [snapback]250516[/snapback]</div>

Actually, we do have control over ICE rev, the "gas" pedal. [/b]

Technically, because it's throttle-by-wire (and computer), the ICE revs only when it wants. Good thing it mostly matches what we want when we push that pedal, but sometimes there could be a very slight lag. Nothing new, as there's many cars now with throttle-by-wire.

[hobbit]

Having a tach is actually really important for good mileage. See
http://techno-fandom.org/~hobbit/cars/prius-curves.gif and by
looking back and forth between the two plots you can see that kW
output maps rather linearly to RPM, and thus that you need to get
up around 1400-1500 rpm before you're decently loading the engine
and making it run efficiently. The whole principle behind pulse &
glide is to run the engine efficiently, or not at all, and a tach
is one very basic piece of instrumentation that helps you see it.
.
Toyota really dropped the ball on that one.
.
_H*

[hdrygas]

<div class='quotetop'>QUOTE(hobbit @ May 5 2006, 08:19 PM) [snapback]250624[/snapback]</div>

Having a tach is actually really important for good mileage. See
http://techno-fandom.org/~hobbit/cars/prius-curves.gif and by
looking back and forth between the two plots you can see that kW
output maps rather linearly to RPM, and thus that you need to get
up around 1400-1500 rpm before you're decently loading the engine
and making it run efficiently. The whole principle behind pulse &
glide is to run the engine efficiently, or not at all, and a tach
is one very basic piece of instrumentation that helps you see it.
.
Toyota really dropped the ball on that one.
.
_H*
[/b]

I agree about Toyota dropping the ball as far as I am concerned but I think that they did not want to over stress the average driver with too many details. I think that they want us to just drive it. They may have over looked the possibility that there just may be a segment of propeller head geeks who have to push the technology to the edge. Thanks to Norm for helping us scratch that itch!

[jburns]

<div class='quotetop'>QUOTE(hobbit @ May 5 2006, 11:19 PM) [snapback]250624[/snapback]</div>

Having a tach is actually really important for good mileage. See
http://techno-fandom.org/~hobbit/cars/prius-curves.gif and by
looking back and forth between the two plots you can see that kW
output maps rather linearly to RPM, and thus that you need to get
up around 1400-1500 rpm before you're decently loading the engine
and making it run efficiently. The whole principle behind pulse &
glide is to run the engine efficiently, or not at all, and a tach
is one very basic piece of instrumentation that helps you see it.
.
Toyota really dropped the ball on that one.
.
_H*
[/b]

I'd rather have a temp gauge. By the time a red overheat light comes on it's to late to do anything to avoid the problem.

[hdrygas]

<div class='quotetop'>QUOTE(jburns @ May 5 2006, 08:29 PM) [snapback]250630[/snapback]</div>

I'd rather have a temp gauge. By the time a red overheat light comes on it's to late to do anything to avoid the problem.
[/b]

You can have that too with the CAN View.

[SW03ES]

The Lexus hybrids have a kW meter, the 600h has an RPM gauge actually...

[8AA]

I've never understood why conventional cars with automatic transmissions have tachometers.