"The CVT: Learn it and Love it"

[The Critic]

Originally Posted By: antiqueshell
Actually the manual gearbox has had a tiny resurgence in the US over the past several years, and it might become bigger because one of the most expensive options on any car is that of the automatic or CVT, you can usually save at least a thousand bucks by ordering a car with a manual transmission, and these days most folks don't have a lot of spare change to waste.

As for the Rest Of the World, the manual gearbox is not going anywhere as most other countries prefer it.

On most cars nowadays, the price difference between an auto and manual is about $1k, if at all.

 

[buster]

It seems to be about a $1k on average. I think with Subaru owners it's a bit different, being they tend to keep their cars a longer period of time. I agree with you what you said though otherwise. It's really a preference.

 

[SwampSurvivor]

I like manual transmissions and I don't like spending money.

People like me will pretty much always end up with a manual when it's available for less cost.

 

[BearZDefect]

Quote:
... The Subaru CVT tricks your ears into believing the Forester has good throttle response, but the accelerator pedal is about as nuanced as a light switch....

A review that agrees with me!

While I don't blame this light switch problem on the CVT, last summer I test drove the 2014 Forester and totally agree with the light switch throttle response. It was the worst I have driven, and I have driven multiple different modern cars with aggressive throttle tip-in. The 2013 Outback I test drove the same day was much more civilized.

 

[BHopkins]

Originally Posted By: BearZDefect
Quote:
... The Subaru CVT tricks your ears into believing the Forester has good throttle response, but the accelerator pedal is about as nuanced as a light switch....

A review that agrees with me!

While I don't blame this light switch problem on the CVT, last summer I test drove the 2014 Forester and totally agree with the light switch throttle response. It was the worst I have driven, and I have driven multiple different modern cars with aggressive throttle tip-in. The 2013 Outback I test drove the same day was much more civilized.


Which engine/tranny did the '13 Outback have?

 

[BearZDefect]

It was a run of the mill 2013 Outback with the standard 2.5 liter four piston engine and CVT transmission. We liked the utility of the wagon, but not enough to pay for unnecessary AWD.

 

[PandaBear]

Originally Posted By: SteveSRT8
CVT's are only durable behind smaller engines. Mfgrs are working on torque capacity but most require a ton of torque management written into the software to protect them.

Regular slushboxes do the same, but can easily handle 500 foot pounds and more while towing and such.

According to the driveline engineer I know a CVT also makes the engines easier to calibrate for mileage due to the steady rpm...


Pretty much.

Also from my school project back then with CVT, the biggest problem is they are constantly gripping and releasing between the belt/pulley or toroidal/disk instead of grip and stay of the clutch pack during cruise. When combined with the constant ratio changing, the amount of wear on the frictional surfaces on CVT are much much higher than on clutch packs. If you ever loses some pressure it would slip and almost immediately wear out a huge chunk of frictional surfaces, and likely kill the unit immediately.

Comparing to 3 speed auto CVT the fuel economy difference is huge, 4 speed is a good amount, 5 and 6 speed it is negligible, especially with variable valve timing that brings you wide power bands.

Dual electric motor IVTs like the ones in Prius are very good, so good that they have almost nothing to wear out on.

 

[SteveSRT8]

Originally Posted By: PandaBear
Originally Posted By: SteveSRT8
CVT's are only durable behind smaller engines. Mfgrs are working on torque capacity but most require a ton of torque management written into the software to protect them.

Regular slushboxes do the same, but can easily handle 500 foot pounds and more while towing and such.

According to the driveline engineer I know a CVT also makes the engines easier to calibrate for mileage due to the steady rpm...


Pretty much.

Also from my school project back then with CVT, the biggest problem is they are constantly gripping and releasing between the belt/pulley or toroidal/disk instead of grip and stay of the clutch pack during cruise. When combined with the constant ratio changing, the amount of wear on the frictional surfaces on CVT are much much higher than on clutch packs. If you ever loses some pressure it would slip and almost immediately wear out a huge chunk of frictional surfaces, and likely kill the unit immediately.

Comparing to 3 speed auto CVT the fuel economy difference is huge, 4 speed is a good amount, 5 and 6 speed it is negligible, especially with variable valve timing that brings you wide power bands.

Dual electric motor IVTs like the ones in Prius are very good, so good that they have almost nothing to wear out on.


Agreed. The new Honda also has basically no transmission, thus it may prove to be very reliable. The Prius has been practically bulletproof in the real world.

With the ubiquitous ZF 8 speed in tons of cars, and nine speeds in Jeeps, then factor in the Ford/GM joint ten speed project, it's looking like the wild west out there for trans choices...

 

[buster]

Quote:
With the ubiquitous ZF 8 speed in tons of cars, and nine speeds in Jeeps, then factor in the Ford/GM joint ten speed project, it's looking like the wild west out there for trans choices...

 

[buster]

I am curious how the CVT Subaru is using holds up in the long term.

 

[MinamiKotaro]

I LOVE the CVT in Mom's VUE, to the extent that I wish my Ion had one. I say put 'em in every car.

 

[SwampSurvivor]

Originally Posted By: MinamiKotaro
I LOVE the CVT in Mom's VUE, to the extent that I wish my Ion had one. I say put 'em in every car.


Aren't CVTs in those prone to failure, basically causing the vehicle to be junked?

 

[Win]

Originally Posted By: SteveSRT8

With the ubiquitous ZF 8 speed in tons of cars, and nine speeds in Jeeps, then factor in the Ford/GM joint ten speed project, it's looking like the wild west out there for trans choices...


You could argue that they are moving to CVT one gear at a time, still I would prefer to have the discrete gear/clutch pack type transmission to a CVT.

I wonder how the CVT's do in a semi performance car? The sport mode on the GM 5L40E is just wonderful at holding gear and keeping the chassis stable through corners. If a CVT does not lock up and hold a gear, what does the chassis do in a hot corner?

 

[SteveSRT8]

Originally Posted By: Win
Originally Posted By: SteveSRT8

With the ubiquitous ZF 8 speed in tons of cars, and nine speeds in Jeeps, then factor in the Ford/GM joint ten speed project, it's looking like the wild west out there for trans choices...


You could argue that they are moving to CVT one gear at a time, still I would prefer to have the discrete gear/clutch pack type transmission to a CVT.

I wonder how the CVT's do in a semi performance car? The sport mode on the GM 5L40E is just wonderful at holding gear and keeping the chassis stable through corners. If a CVT does not lock up and hold a gear, what does the chassis do in a hot corner?


They can be programmed to do anything you want, but they just won't be available in higher horsepower vehicles

 

[buster]

^ not yet at least. WRX is using one.

 

[SteveSRT8]

Originally Posted By: buster
^ not yet at least. WRX is using one.


Sorry, I meant serious levels of hp. If you check them out they are not used beyond certain power levels. Seems to be around that 300 hp mark or so. Wait till the boyz in da hood start ramping up the boost on a cvt equipped model!

Plus, many of the higher powered platforms that do use them have tons of torque management in their programming to protect the trans. This makes them drive funky.

 

[glock19]

Originally Posted By: SteveSRT8
Originally Posted By: Win
Originally Posted By: SteveSRT8

With the ubiquitous ZF 8 speed in tons of cars, and nine speeds in Jeeps, then factor in the Ford/GM joint ten speed project, it's looking like the wild west out there for trans choices...


You could argue that they are moving to CVT one gear at a time, still I would prefer to have the discrete gear/clutch pack type transmission to a CVT.

I wonder how the CVT's do in a semi performance car? The sport mode on the GM 5L40E is just wonderful at holding gear and keeping the chassis stable through corners. If a CVT does not lock up and hold a gear, what does the chassis do in a hot corner?


They can be programmed to do anything you want, but they just won't be available in higher horsepower vehicles


They already tried a CVT in F1 and it got banned because it was too fast. While it took some time, they were able to get it to handle 850 hp...

http://www.auto123.com/en/news/f1-techni...eo?artid=137686

 

[Quattro Pete]

Originally Posted By: glock19

They already tried a CVT in F1 and it got banned because it was too fast. While it took some time, they were able to get it to handle 850 hp...

Sure, you can do anything if you throw enough money at it, but it would be cost prohibitive in a family sedan. I'm sure one day they'll figure it out...

 

[SteveSRT8]

Someone explain how F1 has any relevancy here? Maybe it's still 4 wheels?

http://www.caranddriver.com/features/how-cvt-transmissions-are-getting-their-groove-back-feature

 

[buster]

Good point Steve.

I read that article, which is what got me thinking more about CVT's. They are here to stay for awhile.