Why do automatics have a rev-counter/tachometer?

[esvcg]

i've had 2 autos now, and cannot understand why they have a rev-counter/tachometer when changes are handled for me by electronics and the gearbox, I never even bother looking at it as there's no need - maybe someone can explain?

[LuS1fer]

You can manually shift an auto.

[mrmr96]

Also useful for working out what gear you're in, if there's no gear indicator.
And it demonstrates if the gearbox is changing up at the right times.

The cooling fan on the radiator is controlled by thermostat, but you still have a water temp gauge.

[LocoCoco]

It might be cheaper to build all the dashboards the same/similar???

Haven't got a clue really.

[randlemarcus]

Because cars without rev counters are for pensioners

[AC43]

LuS1fer said:

You can manually shift an auto.

Exactly.

[otolith]

[g3org3y]

esvcg said:

i've had 2 autos now, and cannot understand why they have a rev-counter/tachometer when changes are handled for me by electronics and the gearbox, I never even bother looking at it as there's no need - maybe someone can explain?

If you've never had to refer to the rev counter when driving an auto then you haven't been driving it correctly.

You can alter shifts on how you modulate the throttle and as mentioned, the revs give an indication of the gear at a given road speed.

IMO, there's a lot more than just sticking it in D and nailing the throttle.

[esvcg]

g3org3y said:

esvcg said:

i've had 2 autos now, and cannot understand why they have a rev-counter/tachometer when changes are handled for me by electronics and the gearbox, I never even bother looking at it as there's no need - maybe someone can explain?

If you've never had to refer to the rev counter when driving an auto then you haven't been driving it correctly.

You can alter shifts on how you modulate the throttle and as mentioned, the revs give an indication of the gear at a given road speed.

IMO, there's a lot more than just sticking it in D and nailing the throttle.

Disagree, I can feel what the engine is doing, as well as hear it. I know if I floor it'll drop down and rev high, and if I feather it the car will be taking it easy.

Also most auto-manual mode options still change automatically on the limit.

[E38Ross]

esvcg said:

g3org3y said:

esvcg said:

i've had 2 autos now, and cannot understand why they have a rev-counter/tachometer when changes are handled for me by electronics and the gearbox, I never even bother looking at it as there's no need - maybe someone can explain?

If you've never had to refer to the rev counter when driving an auto then you haven't been driving it correctly.

You can alter shifts on how you modulate the throttle and as mentioned, the revs give an indication of the gear at a given road speed.

IMO, there's a lot more than just sticking it in D and nailing the throttle.

Disagree, I can feel what the engine is doing, as well as hear it. I know if I floor it'll drop down and rev high, and if I feather it the car will be taking it easy.

Also most auto-manual mode options still change automatically on the limit.

I disagree with you. I used the rev counter frequently, certainly when the engine is cold. My rather ancient auto has full manual override, and will NOT shift up when you hit the rev limit, it will shift down though to stop it stalling.

I prefer having a rev counter

[RichTBiscuit]

does your e38 not change up at the Rev Limit? Mine does, even in manual mode!

[E38Ross]

RichTBiscuit said:

does your e38 not change up at the Rev Limit? Mine does, even in manual mode!

Nope, mine doesn't. What year is yours? Maybe they changed it on later cars? Mine is 2000.

[RichTBiscuit]

Interesting. It always annoys me when it changes up at the limit...... mine's a 98' pre facelift.

Do you have your foot right to the floor when it doesn't change up? i.e Full accelerator + kickdown?

[E38Ross]

RichTBiscuit said:

Interesting. It always annoys me when it changes up at the limit...... mine's a 98' pre facelift.

Do you have your foot right to the floor when it doesn't change up? i.e Full accelerator + kickdown?

Yep, it just hits the limiter and stays there, much to my surprise at the time. Maybe they changed it for post-face lift cars? Strange!

[PanzerCommander]

Must be a newer car thing (electronic - hydraulic control rather than just hydraulic) the auto box in my 2006 Mustang GT does not shift up or down if you put it in any of the selected gears it will set of in 1,2,3 without a problem and will simply sit on the limiter (don’t ask how I know) until you move the lever into the next position or D. I don’t know if it will shift down if the road speed means that the revs would be over the rev limiter, and I shan’t be finding out either!

I would imagine that with the over drive switched off it will hold in 4th at the limiter as well.

[nagsheadwarrior]

otolith said:

Thats a nice cluster, is it a Roller?

[otolith]

Yes, not sure which models have that layout though.

[esvcg]

nagsheadwarrior said:

otolith said:

Thats a nice cluster, is it a Roller?

yep, looks like the ghost model.

I think a power reserve dial is much more suited to an auto, the rev counter just seems redundant to me.

[Ozzie Osmond]

So why do manuals have a rev counter?

Engines have had electronic rev limiters for decades and most drivers have ears so the rev counter is obviously unnecessary.

[Waugh-terfall]

esvcg said:

Disagree, I can feel what the engine is doing, as well as hear it. I know if I floor it'll drop down and rev high, and if I feather it the car will be taking it easy.

Also most auto-manual mode options still change automatically on the limit.

Yes, you can, sure, but you're not the world and his dog, are you..?