Newsweek: end coming for Toyota's CVT?

I love my cvt. The lurching in regular transmission cars is really annoying now that I'm used to cvt.

 

My one thought is that the complaints regarding CVTs could be referring to Honda's "belt and cone" (I think that's the term) CVT. I've heard complaints about CVTs like this (particularly early belt & cone CVTs that were in non-hybrids).

The Toyota HSD's CVT? Smooth as glass. As usual, someone's reporting the news without giving it enough detail to be useful.

 

Oh please don't get rid of the CVT, I love it!!! I don't like conventional transmissions anymore, especially after experiencing the smooth CVT in the Prius. The Prius CVT is smoother than my 2003 Lexus 5-speed automatic. It seems that people need to be educated about the new CVT technology. CVT should be touted as something better, no shiftpoints = smoother ride. I'm sure there will always be people who resist change at all costs, but technology marches on. Technological advancements should not be slowed because some people are change-phobic. Those who can adapt to change are always going to be better off. If you make a good effort to educate the customer about the advanced technology, the custom can choose whether to buy it or not.

The article does mention that a CVT is more expensive, so that may be part of the decision. I still love the CVT though. Long live the CVT!!

 

I can't resist chiming in as well; I love the CVT in the Prius. I think it is very smooth, and I have no problem with power needed for acceleration at any speed. I don't understand the problems (perhaps misrepresented) in the article.

 

I really like the CVT in the Prius -- it does not have the lurch or delay of a typical automatic. No complaints from me after 48000 miles in my 2004!

 

I think the CVT in the Prius is a lesson for others.
Everyone I have given a lift to has commented how smoooooth and quiet it is - mind you I've only 500 miles on it and yet to drive it hard or go over 60mph.
Having made the leap of faith however - I wouldn't go back
Pinball

 

The CVT is one of my favorite features on my Prius. SMOOTH.. no shift shock. Great throttle response once underway. I tell you... a majority of drivers are just plain DUMB and STUPID. That brings me to another point. The Prius is the type of car that can only be truly appreciated by those that understand its inner workings. Folks that buy it and expect a conventional car like ownership will complain. I kind of wish the Prius remained a niche type vehicle as before the 2004 was released.

 

Of course you realize the Prius doesn't have a CVT. It's just a planetary gear set. Toyota actually calls it a Power Split Device. The CVT in the Murano that I had was actually smoother than the PSD in the Prius.

Regards,
Chuck Lane

 

In the sense of a conventional car the Prius does not have a transmission. The same for the other HSD vehicles and the Hybrid Escape.

The Power Split Device is integral to the HSD and does just what the name implies. It splits the power from the engine to MG1 and MG2. In doing this it only acts like a CVT.

 

Exactly. To try and simulate gear shifting (the concept is completely alien to the HSD), Toyota would have to put the HSD through some ridiculous -- and unnecessary -- hoops.

I think that you're extremely unlikely to see a non-CVT Prius anytime in the future. It not only wouldn't make sense -- it would be difficult, expensive, and maybe impact mileage & emissions.

 

I haven't researched the subject but, I believe Toyota is the only car company using planetary/reduction gear arrangement which they call Electrically Controlled Variable Transmission (ECVT). Or we can use Graham's term--epicyclic gear and be even more confusing. The conventional CVT uses two conical shaped pulleys placed side by side pointing in oppposite directions and connected by a belt. The engine drives one pulley and the belt drives the other pulley which goes to the differential and then to the wheels. As the belt moves across the pulleys, up the diameter of one pulley and down the diameter of the other pulley an infinite number of "gear" ratios is produced without gears. I do know the Saturn Vue, at one time, and the Honda CVT (hybrids) uses the pulley and belt version. The Saturn CVT was another GM engineering debacle and was removed shortly after introduction.

 

Well, coming from decades of driving manual transmissions, I guess I have a difefrent perspective from most people on this board. I completely understand the feelings of people who don't like the CVT. My friends, its not the smoothness that is the complaint. Its the fact that you step on the gas and the engine revs high. It feels like the transmission is slipping, and for some that can be an unpleasant experience.

Granted, I understand that the Atkinson cycle engine causes the Prius to not have much low end torque, so this revving is the most efficient way for the Prius to accellerate. Though I don't like diesel engines for their pollution, noise, and higher fuel costs (per gallon), maybe the diesel with its immense torque would be really great to have in a CVT hybrid so that the CVT can be programmed to not rev so much, while retaining its smoothness.

My love of manual transmissions is not due to not accepting change. I just don't like the loss of control of engine speed I have with an automatic. I used to always shift early in my other cars specifically because I didn't like the high revving coming from my engine.

 

I agree with ml194152, the first time I drove the Prius I felt the clutch was slipping due to the engine reving out of sync with the acceleration. But as we all know that is due to the fact that we are driving a hybrid, and has nothing (directly) to do with the CVT. The lurching of an automatic transmission is a side effect of that technology. If we can train ourselves to "enjoy" the negative side effect of an automatic transmission, I hope we can train ourselvs to enjoy a better technology. To me, its like saying I will only go to the doctor if the shots hurt because that is what they were like when I was a kid.

 

The Prius already deals with the lack of low end torque due to the atkinson cycle engine...

Namely, motor-generator 2 provides all the torque that you need. During acceleration, you will notice that arrows on the energy screen flow from the engine to the wheels, but also from the engine to the motor, and from the motor to the wheels...

what this implies is that the engine, which isn't very good on it's own at supplying torque, spins motor-generator 1 as it is powering the wheels and generates electricity which is sent directly to motor generator 2... motor generator 2 in turn provides all the torque that the engine can't provide. If more torque is needed, then the system uses electricity from the battery to power MG2 as well.

An elegant system, in my opinion.

I understand that you don't like the sound or the feel of the transmission slipping, but you must understand that fundamentally, it's not going to do any damage, and that high revs don't imply anything is going wrong...

This is part of the reason why so many people have the misconception that the Prius has poor acceleration. They're spooked by the sound and the feel of the CVT, and then consciously or subconsciously hold back on the accelerator... never knowing that the CVT is doing fine and that it has much more potential to give you...