Subaru Ascent Forum banner
1 - 18 of 18 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter · #1 ·
the faux shifting from the CVT. It seems like that is the number one complaint on here is the faux shifting and I for one am glad that Subaru programmed the CVT with it. You really don't notice anything when you push the pedal no more than 1/2 way down, but anything more than 1/2 way down and the faux shifting happens. IMO sometimes it can be jerky but for the most part it feels good and MUCH more enjoyable to listen to than the CVT drone that they are known for.
 

·
Registered
Joined
·
298 Posts
I think this thread will mostly attract those that hate the faux shifting. So I don't expect a lot of posts that will support that. But I am sure there are many that really don't care either way. I am one of those.


But I can see some positives and maybe why Subaru implemented these faux shifts. My other CVT car (Toyota) does not not have faux shifts, and instead you get a very noisy steady drone at high power, which can also be annoying to some. The faux shifts breaks this up, and gives a more nostalgic feel under high power. Also the Toyota has a strong rubber band effect, where it revs up first, then you feel the power surge. The Subaru tends to be more responsive when you press the pedal, and no rubber band effect. And under low power, no faux shifting, just smooth acceleration.


So personally, I don't mind the faux shifting at all. While I don't hate the Toyota CVT and high rpm drone under power, I think I like the Subaru CVT better. But I either way, it really doesn't matter to me.
 

·
Registered
Joined
·
646 Posts
If it were done better it would be ok. But it's so rough compared to the 18 outback and 18 forester loaners I have had. The option to enable or disable it should be standard though.
 

·
Registered
Joined
·
542 Posts
I hope they implement the ability to turn it on and off.

Don’t think it has anything to do with the drone either, it doesn’t drone like our Prius at any rpm.

What it feels like a bad transmission that’s hunting for gears or someone just learning how to drive stick vs the smooth linear power found in electric cars which I feel it can achieve by removing the “shifts”
 

·
Registered
Joined
·
225 Posts
I have mixed feelings about it and I have found that when I do a soft acceleration it gets very confused in when it should shift. I've had a few times where I've accelerated slowly when it is extra cold outside and the CVT seems to go up and down causing the car to gently jerk/rock. If I apply just a bit more throttle this goes away. I don't drive far so my cars usually go 100,000 in 10 years so I will be covered for a while if the CVT decided to poop itself.
 

·
Registered
Joined
·
926 Posts
I love my CVT.


Though I'm not sure if my CVT is different, or maybe it's just because I'm in AZ and it's almost always hot (as some people have complained about the cold) but I don't have hard shifts, even when I did a 1/4 mile drag run while I was testing fuel octane. It does shift but the transition is smooth and not jerky and the rpms are more of a quick wave up and down as it shifts, rather than any abrupt change.


When I stay low-mid throttle it just picks an rpm around 2,000 and smoothly accelerates without a hickup.


Even behaved nicely when towing a 3,500 lb camper up the mountains.
 

·
Registered
Joined
·
85 Posts
That is true you probably are the only one who likes it, but to each his own. That's what makes this a great country! I just hate the way it falls on its face at slight throttle from a stop. It upshifts too fast. If I use the paddles I can get going quickly with the same throttle. My old 2010 just revved up and stayed. Always smooth. Yes it droned but that was ok.
 

·
Registered
2020 CWP Touring
Joined
·
1,256 Posts
I don't mind the simulated shifts at high throttle. Because the OP is right -- it happens only at higher throttle openings (more than 50-60% in my experience). I voted for the "user selectable" option in the forum poll, because some probably do like it and some probably don't. This thread is a good balance to those of us who don't care for it, because some do prefer it and that's obviously why Subaru implemented them. It cost Subaru additional development time and resources to program in the shift points and ratios and how they would work, etc...so they obviously did it for what they felt was a compelling reason.

I would prefer the simulated shifts to be a little smoother. They are generally pretty abrupt, and disruptive to passengers. Our CVT has about 3,800 miles on it now, and they do seem to be getting a little smoother...maybe that stuff takes time to break in.

I'm with @NTD ... the real show-stopper for me is the aggressive ratio change at low throttle openings from a stop. The throttle mapping in general is very weird and unpredictable. At slower speeds, the car seems to need a lot of throttle to get going (about 25% indicated for "moderate" acceleration). But give it that much throttle at road speed and you'll rocket ahead like you got shoved in the back by a semi truck. It's very unpredictable and it's taking a long time for me to learn how to drive this car smoothly.

I think the powertrain is brilliant. I just love the engine and transmission. I think I'd do much of the programming differently if I had the choice. Sadly, that's what drove me to Subaru and its CVT to begin with. I typically don't like the programming in stepped automatics (they usually try to upshift more often than I'd like). I thought the CVT in the Ascent would be a panacea for me, but it has not been. It's no worse than other automatics I guess. (Small praise?) I do love it on the interstate...no up/downshifting. It's very smooth when using ACC. I wish it'd be as smooth when I'm using the gas pedal.
 

·
Registered
Joined
·
85 Posts
How true. You are right on the money when noticing the low end shift, why?! Get the car rolling and then shift. I am a firm believer this is why the town mileage suffers a little.
 

·
Registered
Joined
·
223 Posts
I recorded a video showing the faux shifting. I would say it is disruptive for sure.

regarding the very low end throttle up shift. It seems to occur Below 2000 RPM. If you have all day and really want to granny it you can accelerate at 1500RPM but it slow and takes a long time to get up to speed. . watching real time Fuel consumption it appears it’s not even that efficient. I agree this is partially why city mileage is poor. I have found 2000-2200 RPM is the smoothest with decent acceleration and probably better on fuel efficiency.BTW it starts to call for turbo boost around 2200. Typically with 1psi only that’s all it takes.
 

·
Registered
Joined
·
85 Posts
I agree with you. You have to get the rpms to a suitable level to avoid that low end shift, hence get rid of the fake shifting and a lot of customer complaints disappear and mileage will go up. Thanks for your post!
 

·
Registered
2020 CWP Touring
Joined
·
1,256 Posts
BTW it starts to call for turbo boost around 2200. Typically with 1psi only that’s all it takes.
The ECM modulates the wastegate electronically, and it's driven by a lot of factors. If you're in manual mode (to hold the engine speed down), you can get moderate boost (5+ psi) at only 1,500 or so RPM. It'll hold boost to lower figures when engine speed is that low to prevent engine damage, but boost is managed by the computer and is generated in response to many factors...engine speed is one of them, but only one of them. The maximum boost I've seen is in the 15 psi range.

It is interesting to watch the ECM try to stay out of boosting the engine unless you're really pushing it. It'll have the throttle butterfly wide open, even when you're at less than 50% on the gas pedal, to try to get the most out of the 2.4 liters of displacement without pressurizing the system. It seems to quickly ramp open the throttle butterfly as you ease into the gas pedal and, only if naturally aspirated wide open throttle is not enough, vacuum will start to turn negative (indicating pressure). I think it's pretty fascinating to watch the computer manage the engine load and other parameters when trying to stay out of boost (to save fuel, obviously).

In our case, I don't find a lot of difference in fuel economy when driving it in manual mode vs. stepless mode. We average in the low 20s around town, which I'm 100% happy with. The deep gear ratio change just off idle is done while maintaining about 50-60% engine load, which actually keeps efficiency high. It requires more throttle opening (which reduces pumping losses), but the ECM hasn't closed the wastegate on the turbo to pressurize the intake...so economy tends to still be pretty good. There really is not a linear relationship between gas pedal and throttle butterfly opening...which definitely takes some getting used to. I don't like that deep ratio change, but I really do think the car is doing what it can to support good fuel efficiency.
 

·
Registered
Joined
·
85 Posts
You could be right. It's just so darn irritating and rough feeling. Not like a 41k. Car should feel like. Thanks for the info it does shed some light on a few things and I am thoroughly impressed with your knowledge of this system!
 

·
Administrator
Joined
·
11,089 Posts
The ECM modulates the wastegate electronically, and it's driven by a lot of factors. If you're in manual mode (to hold the engine speed down), you can get moderate boost (5+ psi) at only 1,500 or so RPM. It'll hold boost to lower figures when engine speed is that low to prevent engine damage, but boost is managed by the computer and is generated in response to many factors...engine speed is one of them, but only one of them. The maximum boost I've seen is in the 15 psi range.

It is interesting to watch the ECM try to stay out of boosting the engine unless you're really pushing it. It'll have the throttle butterfly wide open, even when you're at less than 50% on the gas pedal, to try to get the most out of the 2.4 liters of displacement without pressurizing the system. It seems to quickly ramp open the throttle butterfly as you ease into the gas pedal and, only if naturally aspirated wide open throttle is not enough, vacuum will start to turn negative (indicating pressure). I think it's pretty fascinating to watch the computer manage the engine load and other parameters when trying to stay out of boost (to save fuel, obviously).

In our case, I don't find a lot of difference in fuel economy when driving it in manual mode vs. stepless mode. We average in the low 20s around town, which I'm 100% happy with. The deep gear ratio change just off idle is done while maintaining about 50-60% engine load, which actually keeps efficiency high. It requires more throttle opening (which reduces pumping losses), but the ECM hasn't closed the wastegate on the turbo to pressurize the intake...so economy tends to still be pretty good. There really is not a linear relationship between gas pedal and throttle butterfly opening...which definitely takes some getting used to. I don't like that deep ratio change, but I really do think the car is doing what it can to support good fuel efficiency.
Yep. And if you go all out, you will get enough boost that you'll be at max 277 lb-ft of torque when you hit 2,000 rpm.

The ECM will keep the variable wastegate at an open state to make no more than the torque limit...

Watching the wastegate solenoid requests on my AccessPort shows its virtually always active.

Reading the wrong data points shows the wrong state.

Watching vacuum vs boost doesn't seem to give an accurate representation of what's really going on.

One day, I may try recording all of the data and compare.
 

·
Administrator
Joined
·
11,089 Posts
There really is not a linear relationship between gas pedal and throttle butterfly opening...which definitely takes some getting used to.
LOL, yeah, the computer is pretty much like "I know what you asked for, but here's what I'm going to do". 😂

The response curve, as well as the interesting tip in point for a jump in power is interesting. And, it seems to be affected by the speed the pedal is actuated. For instance, I can do smooth acceleration from stop to full throttle, and even avoid most or all faux shifts, by doing a relatively consistent pedal press at the right press-speed, if that makes sense.
 
1 - 18 of 18 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top