This may reflect my general ignorance of mechanics, but why does my CVT-equipped car have a tachometer? Isn’t the whole point of CVT that it should keep the engine rpms as close to optimal as possible and therefore make having the tachometer sort of pointless?
That’s a good question. Tachs are pretty much ignored in all cars with automatic transmissions, but folks seem to like having them, so makers keep including them. Gearheads like them, but they serve no real purpose 99% of the time.
Now you’ll read the gearheads’ side…
texases wrote:
Tachs are pretty much ignored in all cars with automatic transmissions, but folks seem to like having them, so makers keep including them.
I often hold my Acura MDX in second gear for merging and passing. I’d prefer not to get too close to the redline when doing this, so I definitely use my tachometer then. I’ll admit most drivers probably don’t do this, of course.
There is still some variation in rpms even with a cvt. Maybe it’s jst part of an instrument cluster that’s hard to part with. Some CVTs still have some manual overide that might require some consideration for the motr rpms. Either way, I’m in favor of keeping it in a tack.
Tachs are useless. There’s a use for them in race cars with standard shift. But I’ve never seen a need for them in any car I’ve ever owned. I’ve heard some people say that they use it for shifting…All I have to say is…learn how to listen to your engine and keep your eyes on the road. Learning to shift with your ears is far better then shifting with your eyes.
But as @Texases said…people like them.
I’d rather see gauges like - oil temp, tranny fluid temp and oil pressure gauges …instead of idiot lights. Those gauges are useful.
Sports cars put the tachometer front and center even though speed is what the driver mostly needs to monitor.
Even the owners manual for our automatics give the recomended maximum shift points you should use to downshift for engine braking. The motors on some of my cars have been so quite, using the tachometer instead of your ears seems a little more appropriate. I definitely like having it on one SUV with a low range. It’s very easy to over rev it in low range. Even if the computer keeps you from over revving the motor, I personally would not use engine braking downshifting at speeds higher then 75% of the redline. Again, maybe I am the exception but, I always appreciate having a tachometer. The health of the motor and transmission can definitly be tied to monitoring the tachometer.
As far as fluid and oil temperature gauges are concerned, they may make a knowledgable person a little more aware of the cars operating conditions but they are a lot less important in the actual operation of the car for the average driver. Tachometers are definitely more useful or should be.
The motors on some of my cars have been so quite
It’s more feel then hearing. If you know how to drive a standard…you should NEVER need a tach to determine your shifting. As for low range 4wd…Yea it is a little useful there…but I rarely use low range…and most people I know with 4wd systems have never used low.
The automaker can only provide the components ( Like low range and a tachometer). They obviously can’t demand that owners properly use them. They can and do recomend their proper use in the owner’s manual. Maybe those who own and never use low range should consider that the next vehicle they buy a vehicle with one. I have a need and use it enough to justify having it. Same for a tachometer. Maybe people should be doing more engine braking when driving as recomended too. Never need a tach when driving a manual ? When I drove a dump truck with a load, my boss gave me explicit instructions; engine brake a lot and don’t use engine speeds higher then “----” Manuals are much more in need of a tachometer, not less. I would hate to operate any manual transmission work or sport vehicle without a tachometer.
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I got my 1st car I had with a tachometer after 19 years of driving. It looks nice there, but don’t need it.
When I drove a dump truck with a load, my boss gave me explicit instructions; engine brake a lot and don't use engine speeds higher then
I thought this was a forum about cars…NOT dump trucks. Yes dump trucks and excavators and 18 wheelers the need for a tach is probably justified. I’ve driven and owned many different manual vehicles over the past 40 years of driving. From Camaro’s to F150 pickup and Vega’s to Nissan Pathifnders…and Dodge Aspen…and I’ve never ever NEEDED a tach to tell me when I needed to shift. And I guarantee you I was shifting at proper shift points. Maybe not so much on my Vega because that was my first manual.
The automaker can only provide the components ( Like low range and a tachometer). They obviously can't demand that owners properly use them.
First off…show me the 4wd vehicle that comes WITHOUT low range? I’ve yet to see it. If they do exist…they are rare. Many people may need 4wd…but have no need for low-range. In fact I’ll give a guess that low range is probably needed less then 1% of the time. I rarely use it. But when I need it…it’s surely nice to have.
Tachs are mainly a marketing gimmick. Just because it’s standard equipment doesn’t mean it’s a useful item.
"The tachometer…use it while driving to select correct shift points to prevent engine lugging and over revving. " (from two Toyota manuals, both with automatics.)
Many automatics like manuals allow you to select gearing for engine braking, towing, in town driving. I know some superior drivers can tell the exact engine speed just by listening but the manufacturer must feel a few can’t.
"The tachometer.....use it while driving to select correct shift points to prevent engine lugging and over revving. " (from two Toyota manuals, both with automatics.)
And in my opinion…and many others that actually know how to drive a manual…if you can’t do that by feel…you have no business driving a manual. And what are those shift points?? In fact the whole notion of using a tach for shifting is laughable. The shift point will vary depending on the terrain you’re on and the load you’re carrying or towing. Is Toyota going to give you a spread sheet to read to determine what the shift point will be when you’re carrying 500lbs extra and going up a 2% grade?? Because it’s NOT going to be the same when you’re driving by yourself on a flat road.
I know some superior drivers can tell the exact engine speed just by listening but the manufacturer must feel a few can't.
MOST people I know who can drive a manual NEVER EVER look at the tach. And IMHO…if you’re constantly looking at the tach…you’re NOT paying attention to what you should be doing…like looking at the road. A tach in MOST cars is just another useless distraction that should be eliminated.
When I drove a stick, I rarely used the tach. I always shifted when the engine sounded like a shift was needed; up or down. I looked more for downshifting than up shifting.
The question originally was, why a cvt needed a tachometer not why a manual does or does not. I drove manuals for 40 years without benefit of a tachometer too, but that is not what the discussion is about IMO. Because most drivers drive automatics and have never driven a manual transmission but are now driving autos with shift selectors, owners manuals refer to watching the rpm gauge to keep from selecting the wrong gear and over revving or lugging the motor, when engine braking, towing, driving around town or accelerating. Some of these options are specifically mentioned on my owners manual as needing the driver to pay attention to the rpm gauge " WHILE DRIVING AN AUTOMATIC".
IMHO, drivers without manual transmission experience NEED an rpm gauge more…if they want to use the shift selections that some autos provide. That seems to be why autos have tachs. That’s what the owner manuals say in my cars and that I believe I’d what the discussion is about
and not whether some one should be driving manual or not with a tachometer.
Texases said it perfectly.
I drive an automatic now, and it has a tach. At first I couldn;t see the point, but now I kind of like having it. I makes me feel young.
Oddly, I never had a tach in any of my manual trannys. Never needed one. It’s pretty tough to not know by feel and sound when it’s time to shift…unless, of course, one is driving a supercar. Modern cars that do have the ability to blow past the redline are electronically limited anyway.
In summary, nobody in a stock car really needs a tach. But they’re nice to have. Sort of like that “polished aluminum waterfall” that drapes down the center of your dash and turns into a console.
Same. You are correct of course that most newer cars can’t be over revved . But according to manuals, that doesn’t keep people from
Running around in the wrong gear in an auto and having the motor revving too high or too low for an intended purpose.
There’ll always be a few. But I don’t think a tach makes a bit of difference. People who are aware enough to know what the numbers mean are either doing it on purpose or don’t care. People who aren’t don;t know the difference anyway. By the time the enine gets into a zone that will begin to make a difference to it, the driver can’t ignore the noise.
I really don’t see the point in having a tach with any car with an automatic transmission, CVT or conventional automatic. A tach is useful in a manual transmission car, but if you are not on a racetrack you can shift a manual “by ear” pretty effectively.
There are some special situations where a tach in a vehicle with an autotransmission is helpful, but mostly these situations involve tow vehicles with trailers hooked up and would tend to be pickup trucks or full sized SUV’s. In effect I’m talking about using engine braking without over reving the motor in steep mountain downgrades.