Drove a 2010 CVT Legacy last week down a very steep hill. Used the
paddles to take it down to what it considered first gear (displayed as 1
on the dash) while leaving the console shifter in Drive. Engine braked
like a champ and I don't think it would've been any noisier than a MT
Had I not used the paddles? It would've sailed down the hill with the
dash indicator always displaying D and probably not slowed down had I
not applied the brakes or crashed into something.
At the end of the hill, I used the paddles to get it up into 2nd or 3rd,
but hitting the accelerator will eventually force the CVT to seek out
whatever drive ratio it sees fit, essentially ending the manual input of
the driver and going back to D.
Bless you, Steve--actual real-world experience!
That's interesting about dashboard display--did it start with "D" or
"3" or some such and changed as you geared down?
I'm glad you chose to try the gear-down approach instead. :-) I'm sure
that the Legacy appreciated it as well...
Speaking of noise...last time I was coming down the aforementioned
grade near Yosemite, the friend who was in my Legacy Wagon with me
asked whether the car was okay, because the engine had gotten pretty
noisy. I pointed out that it was only going around 4,000 rpm and
redline is about 6,500, so although it sounded in some distress, it
was fine. :-) Yeah, it's louder at 4K than my Porsche is, but I don't
care; I don't do that very often.
Hi Patty. Steve again from Google this time. The dash display is
always D unless you intervene with the paddles. Once you do that, it
does from 6 to 1, depending on what "gear" you want to be in.
Good question about where the display starts once you begin to use the
paddles. I didn't pay attention to it in that particular case.
I've not tested the console shifter in its "Auto-Manual" mode, but I
suspect it would stay in whatever gear you select, unless you try to
go over redline or bog the engine by driving too slowly. In
traditional Drive, the CVT will go back into it's normal thing if it
doesn't detect further input from the paddles, or you hit the gas or
"When using the "manual shifter" mode, did the ratios change suddenly
like in a real manual, or gradually & smoothly?"
It was sudden, though as I remember it the downshifts were snappier than
the upshifts. You could be in first and paddle it up to sixth as fast
as you like, but I think it wouldn't automatically go into that top
ratio if the vehicle's speed didn't warrant it yet. You'd probably have
to be on the gas for all of the upshifts.
Does not remind you of your dentist equipment? (pun intended)
And yes, firewall sound deadening IS expensive as tens of southands of
chinese autoworkers deadening firewalls could probably attest by now.
Manual labor mostly I think.
And where the heck is SOA with an eduficational video when
there is such a wide area open for speculation? :^)
Well, this is the type of feedback I was hoping for, so thanks for that,
Steve. So even CVT's need manual intervention with those paddles to
engage the engine brake on a long downhill to stay within speed limit.
It confirms my original suspicion that a car computer could not possibly
know such things. Those paddles are probably acting as some kind of
wedges to prevent the drive pullies automatically change the drive ratio
that would normally happen during acceleration.
When I think how simpler CVT's are compared to conventional A/Ts, I
don't understand why CVTs did not become the "conventional" A/Ts right
from the getgo, instead of the way-compex alternatives most cars use today.
I understood it. But then, I'm a mechanical engineer so I have a
professional responsibility to understand things like that.
I have no idea, however, how a Subaru CVT works. Swash plate?
Variable diameter pulleys? Torque converter?
Some 40 or 50 years ago a Dutch company called DAF imported to the
US a small car with a CVT based on variable diameter pulleys. A
friend had designed a transmission like that as a senior-year
project in mechanical engineering, and bought a used DAF out of
curiosity. The first lesson learned was that the DAF could be
started while in gear; he learned this when his wife started it up
and rammed it into the back of their other car. The DAF wound up
sitting at the curb until the weeds grew up around it, the neighbors
complained, and he had to have it towed away.
That has nothing to do with Subaru but I think it's a funny story. I
doubt variable diameter pulleys could transmit the torque of a
The CVT has an infinite gear range, there is no single lower gear it can
select to go slower, but it can select any gear ratio (or rather roller
ratio) very smoothly to maintain the same speed. It should work the same
uphill, downhill, or level.
**I was reading the new issue of Consumer Reports yesterday. They
compared the new Impreza and Mazda 3. Here's a kinda relevant bit for
" Reduced weight, a new CVT, and a 148-hp, 2.0-liter four-cylinder
engine helps the Impreza get slightly better acceleration and 3 more
mpg than the previous model. But the CVT provides too much engine
braking on downhills."
Under the term Lows: Noise, excessive engine braking.
Now THAT is and interesting and useful info in this topic. I just
wonder how that excessive engine braking comes about. I suppose when a
driver lets his/her foot off the gas pedal on a downhill which is
probably not as doable with CVT as with conventional A/Ts. It appears
that with CVT one would not want to take the foot off unless wanting to
decelerate fast. To me excessive engine braking is still preferable to
inadequate one. However, the noise is not something I would be looking
for with a good engine brake.
**Here's a paragraph on the noise issue:
"Noisy cabins are weak points in both cars. The Impreza's continously
variable transmission tends to hold engine revs high, which amplifies
engine noise. But the Mazda is even worse, suffering from conspicuous
road noise that drones on the highway."
On Saturday, April 14, 2012 1:08:01 PM UTC-5, cameo wrote:
I think I have read of one person that complained about the reduced ability of the CVT equipped Outback to engine brake down an extreme slope where they lived. It seems to have been only related to the increased engine idle when the car was cold. maybe under that condition, Subaru should consider some type of re-programming of the system.
You could ask for feedback from CVT owners at subaruoutback.org or ultimatesubaru.org Forums.
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