many-speed automatic vs CVT?

[etherealfocus]

Just read a Dailytech article about companies coming out with 7-9 speed auto transmissions to meet upcoming CAFE standards.

I'm wondering what the point is. Why bother developing very complex automatics when they could just throw a CVT in and be done with shifting altogether? I'd imagine CVT is probably more complex than the basic 4-5 speed autos we're used to but compared to a 9-speed? I'd imagine CVTs are simpler, and require less development since we've already got a variety of them. Probably less weight too.

Is there some downside to CVTs I'm not aware of?

Note: I'm not a big car person, just a curious nerd. Be gentle.

 

[imagoon]

[automotive] CVT's currently have longevity issues with high horsepower \ torque engines. Actually modern automatics are much simpler than the older units. Mostly because the electronic brains are "simpler" than the older hydraulic controllers. That is the main reason the 8 and 9 gear transmissions are "possible" while being lighter and smaller than older 4 speeds.

 

[Safeway]

I've never driven a CVT, but I hear they feel horrible.

 

[JCH13]

I've never driven a CVT, but I hear they feel horrible.

The last time I drove a CVT I was quite impressed with its responsiveness. Of course CVT performance probably varies widely.

OP: imagoon has it right on the money. CVTs are quite complicated mechanisms that I don't believe are as well understood as gears and clutches.

 

[Railgun]

[automotive] CVT's currently have longevity issues with high horsepower \ torque engines.

Or just plainly can't handly higher output engines.

I've driven several, mostly all Nissan (biggest proponents of it I think). Every last one has felt horrible. The earlier ones I've driven felt as though they would slip into a better ratio as you let off the gas, so you would feel a slight pull (read: extra bit of acceleration) for a split second. Strange feeling.

While the idea is nice, it's application is not for anyone who even remotely considers themselves automotive enthusiasts.

As for the 8+ speed motors, if you were going to rip a manual out of my hands, that as a dual clutch variant I would gladly take.

 

[etherealfocus]

@Goon I'd imagine most performance-oriented enthusiasts still love their stick shifts. Ditto for hypermilers.

CVTs and automatics seem like they hit the target: commodity daily drivers. Small 4-6cyl engines, low to moderate emphasis on performance, etc. CVTs seem like a good fit for that (of course, I know way better than the automakers - lol).

I didn't realize modern automatics were so much improved. What years would you say make a big difference in transmission quality?

I'm pretty happy with my 2007 Versa hatchback 6-manual but the gearing is a bit low (2000rpm@45mph in 6th gear) and the CVT option does have a much higher top ratio. Would prob result in decent gas savings considering all the freeway miles I drive, but that option was a little spendy.

Still, how new a vehicle should I be looking at if I wanted to test drive a 'modern' automatic? Any recommendations for a good daily driver done right?

 

[PricklyPete]

From my understanding, there are three major reason's that 8+ speed transmissions are favored over current CVT technology:

1) Ability to handle power - current CVT's are mostly relegated to lower power input applications due to strength of design.

2) Gear spacing - You can put a much wider gear ratio in an 8+ speed automatic than in the current CVT technology. This can result in a much more efficient overdrive for the automatics.

3) CVT's feel like crap relative to what we are used to. I have only extensively CVT's from one manufacturer...Audi. I had one in Europe 3+ years ago in a B7 variant A4...and it was HORRIBLE. I recently had one in a FWD loaner when I was getting our car serviced...and it was much, much better than past implementations.

It will be interesting to see how it plays out. Now that my wife and I are staying stateside, we are going to start looking for a new car soon. We are thinking about getting her something new and the Subaru Outback keeps coming up. I hate the idea that it has a CVT...but it gets an impressive 2+ MPG in both city and highway with the CVT vs. Manual. Not to mention my wife does not drive manual. I'm interested to see how it drives.

 

[Spicedaddy]

CVT is the best for daily drivers/gas mileage. You feel disconnected from the car, but then again I've never driven a torque converter auto that felt sporty. I went to Florida in a new CVT Sentra, and you get used to it. Can't beat 1800rpm at 75mph for gas consumption and I actually liked the smoothness after a while...

My car has a DSG tranny and I love it. Feels almost as good as a manual, but no clutch pedal in traffic. It's the best compromise if you only have 1 car and like to drive.

I had a brand new Jetta loaner with a 6-speed auto and it felt like crap.

 

[imagoon]

@Goon I'd imagine most performance-oriented enthusiasts still love their stick shifts.

I drive six-speed Mazdaspeed6 so yeah.

The electronic auto (not talking the dual clutch "auto manuals") were a late 80's to current thing depending on the manufacture. They got lighter since now a mini computer controlled the solenoids vs the quite elaborate hydraulic "computer."

The hydraulic computer is a engineering marvel btw.

 

[Zenmervolt]

One big issue with a CVT that doesn't get touched on very often is that they tend to have a limited range between the lowest and highest ratio, especially the toroidal CVTs used in higher-torque applications (e.g. Nissans "Extroid" CVTs). While a CVT can choose from an infinite number of ratios, this "infinite" amount only exists between a set maximum and minimum.

There are ways of getting around this (Nissan uses at least two CVT units coupled one after the other to achieve a wider range from minimum to maximum), but those increase complexity more than adding gears to an automatic typically does.

ZV

 

[nismotigerwvu]

The last time I drove a CVT I was quite impressed with its responsiveness. Of course CVT performance probably varies widely.

OP: imagoon has it right on the money. CVTs are quite complicated mechanisms that I don't believe are as well understood as gears and clutches.

Actually the Autoblog podcast hit on this a few times in the past few weeks. I'm not sure what you drove, but the Nissan CVT paired up with a VQ is actually pretty good for what it is. One of the hosts even referred to the VQ as the "cure-all for bad transmissions", which is actually more a statement about needing a wide powerband for a CVT to shine than anything special about the (mostly wonderful) VQ itself. If there was a CVT that could stand up the torque of an LSx I'm sure it would drive like a dream.

 

[Spungo]

I've never driven a CVT, but I hear they feel horrible.

It probably depends on how the computer controls the CVT. Think of it like driving a manual and shifting differently. With the exact same car you could have a wildly different feel based on which gears are being used at certain speeds. One could program the CVT to be sluggish and efficient or one could program it to be high performance.

 

[SpatiallyAware]

I've driven a bunch of them, and they're all pretty terrible in my experiences.

 

[jagec]

I always wondered what it would be like to drive a manual (driver-controlled) CVT. It seems like it would be complicated to get used to, but once you did it might be quite nice. You could basically keep your foot on the gas with the engine at peak RPM and slide the ratio up for max acceleration, or be cruising on the highway and adjusting your ratio on uphills just enough to keep a steady speed at minimum RPM for max fuel economy.

It'll never happen, of course, it would be WAY too complicated for the average driver.

 

[SpatiallyAware]

I always wondered what it would be like to drive a manual (driver-controlled) CVT. It seems like it would be complicated to get used to, but once you did it might be quite nice. You could basically keep your foot on the gas with the engine at peak RPM and slide the ratio up for max acceleration, or be cruising on the highway and adjusting your ratio on uphills just enough to keep a steady speed at minimum RPM for max fuel economy.

It'll never happen, of course, it would be WAY too complicated for the average driver.

Most of the ones I've driven basically use the throttle to control the CVT unless you floor it.

 

[JCH13]

Actually the Autoblog podcast hit on this a few times in the past few weeks. I'm not sure what you drove, but the Nissan CVT paired up with a VQ is actually pretty good for what it is. One of the hosts even referred to the VQ as the "cure-all for bad transmissions", which is actually more a statement about needing a wide powerband for a CVT to shine than anything special about the (mostly wonderful) VQ itself. If there was a CVT that could stand up the torque of an LSx I'm sure it would drive like a dream.

It was a Nissan Altima

 

[BrunoPuntzJones]

I dunno what the Prius has, Power Split Device or something like that, but it sure is nifty. Car never "jolts" except from park into gear.

 

[nismotigerwvu]

It was a Nissan Altima

I didn't want to say it, but that's what I was guessing. Did it have the VQ or was it the QR25?

 

[Doppel]

The VQ + CVT in the Altima and Maxima is not terrible. The main problem--really the only one from the driver's perspective--is that it is not as responsive as it should be. As far as I'm concerned with enough money and development of a CVT it should be a marvelous experience. Imagine you are going along at 1500 rpm and punch the throttle--there's no reason the engine should not almost immediately rush up to max HP. Unfortunately in the current Nissans it doesn't; if you floor it from a stop you can wait a good 2-3 seconds for it to let the RPM get to their optimal range.

I've not driven a 2013 Altima but I read that 70% of its CVT parts are changed from previous gen and that the V6, for example, is hitting 60 almost a half second faster than the 2012--with the same engine. If that's true it must mean Nissan has really revamped the transmission to a huge extent. The 2013 Altima 4 cylinder is getting the best mileage of any non-hybrid mid-size, so its efficiency promises are being realized. I'd just personally love to see a hyper-responsive unit--one that lets your RPM when you floor it get up to peak HP as quickly as if you had floored the car in neutral. The VQ+CVT in the Altima has a "sporty" mode that increases responsiveness as it is, but I'd love to see it damn near uncomfortable to use an ultra snappy as it changes its ratio.

 

[RU482]

I picked up a 2012 Altima 4-cyl on fire sale. I will say that a CVT is better by far than the 4-spd GM autos I had been driving. I've put about 500 miles on so far, and am averaging 34.5MPG on my 25 mile interstate commute.

Before buying that, I drove a 2012 Impala w/6spd....gawd it was almost worse than the old 4spd, certainly didn't feel like 300HP and the car didn't know what gear it should be in most of the time. Also drove a '12 Fusion Sport, wasn't terribly impressed with the shifting on that beast either

 

[nismotigerwvu]

The VQ + CVT in the Altima and Maxima is not terrible. The main problem--really the only one from the driver's perspective--is that it is not as responsive as it should be. As far as I'm concerned with enough money and development of a CVT it should be a marvelous experience. Imagine you are going along at 1500 rpm and punch the throttle--there's no reason the engine should not almost immediately rush up to max HP. Unfortunately in the current Nissans it doesn't; if you floor it from a stop you can wait a good 2-3 seconds for it to let the RPM get to their optimal range.

I've not driven a 2013 Altima but I read that 70% of its CVT parts are changed from previous gen and that the V6, for example, is hitting 60 almost a half second faster than the 2012--with the same engine. If that's true it must mean Nissan has really revamped the transmission to a huge extent. The 2013 Altima 4 cylinder is getting the best mileage of any non-hybrid mid-size, so its efficiency promises are being realized. I'd just personally love to see a hyper-responsive unit--one that lets your RPM when you floor it get up to peak HP as quickly as if you had floored the car in neutral. The VQ+CVT in the Altima has a "sporty" mode that increases responsiveness as it is, but I'd love to see it damn near uncomfortable to use an ultra snappy as it changes its ratio.

I agree, a REAL sport mode would be nice. Maybe give us a 3 stage switch; eco, standard and sport.

 

[foghorn67]

The VQ + CVT in the Altima and Maxima is not terrible. The main problem--really the only one from the driver's perspective--is that it is not as responsive as it should be. As far as I'm concerned with enough money and development of a CVT it should be a marvelous experience. Imagine you are going along at 1500 rpm and punch the throttle--there's no reason the engine should not almost immediately rush up to max HP. Unfortunately in the current Nissans it doesn't; if you floor it from a stop you can wait a good 2-3 seconds for it to let the RPM get to their optimal range.

I've not driven a 2013 Altima but I read that 70% of its CVT parts are changed from previous gen and that the V6, for example, is hitting 60 almost a half second faster than the 2012--with the same engine. If that's true it must mean Nissan has really revamped the transmission to a huge extent. The 2013 Altima 4 cylinder is getting the best mileage of any non-hybrid mid-size, so its efficiency promises are being realized. I'd just personally love to see a hyper-responsive unit--one that lets your RPM when you floor it get up to peak HP as quickly as if you had floored the car in neutral. The VQ+CVT in the Altima has a "sporty" mode that increases responsiveness as it is, but I'd love to see it damn near uncomfortable to use an ultra snappy as it changes its ratio.

There are similar IIRC (or possibly greater improvements) in the cars treated with a ZF 8 speed. Like the Audi A4 and the Chrysler 300c/Dodge Magnum.

 

[amdhunter]

CVTs drive me nuts. I always feel like I need to shift when driving one. Granted, I only drove 2 really crappy CVT cars. Lancer and Nissan something, whatever their cheap brand is, I don't remember.

 

[Throckmorton]

I had a Nissan Versa rental car with CVT and it felt kind of like driving a rubber band

 

[Meghan54]

Having driven our '03 Murano with its CVT for almost a year now, it's not as bad as some try to make it. (Understand, we've only put 20K or so on it, but I think that's enough to make an informed opinion on it.)

True, at low speeds, its response isn't overwhelming and can seem lackluster and slow. But lacking shifting jolts does make up for it a bit.

And once one learns how to drive with the CVT----need better response and quicker acceleration? Put it into sport mode.---it's not bad at all, really. Sport mode really wakes up the 3.5L V-6 in the Murano and cruising at 75mph @ 1750rpm isn't terrible, either.

It does take a beat or two to hit full on rpm's when you stomp the gas pedal, but then again, it's not a horrible lag---a second or two---about what you'd expect any auto to have trying to get the engine up to full rpm's. The nice part is if you hold your foot to the floor, it just keeps those rpm's at 6200 or thereabouts until you let up.

Of course, the current wave of CVT's seem really biased towards fuel economy settings, meaning the darned trans. gets into its lowest "gearing" as quickly as possible. Sport mode, on the other hand, sort of fixes that...but I wouldn't drive around town in sport mode. The throttle response is much, much quicker in that mode, but having the engine always at or near its peak rpm is a bit much for just cruising around at 35-45mph. It does make getting/merging on a highway/interstate interesting, though.

Seems to handle towing pretty well, too. We have towed near or at its max. capacity rating (our "large" boat was weighed at 2649#, fully loaded), and neither the vehicle nor the trans. seemed to struggle at all.

So far, we're satisfied with the CVT's performance.....wife loves it completely. I, a devout manual trans. user from waaaay back (back when 3-on-the-tree was the "standard" manual trans.), have found it can be more than just tolerated.