Conventional Transmission or CVT (continuously variable transmission)?


#1

I am in the market for a new car. Several car manufacturers (Honda, Toyota, Nissan, Hyundai) offer CVT transmissions but no American car companies.The Honda dealer I was at yesterday told me they have been around since 1993. I have never heard of CVT’s before. What exactly is a CVT.? How do they differ from a regular transmission? What about reliability and maintenance? Reliability is critical in my buying decision. I test drove two 6 cyl… Accords, one CVT and one 6 speed automatic. I thought the 6 speed had a smoother, quieter operation. Also drove an Altima with a CVT. Does any one manufacturer have a better reliability, track record than any other? Any information and help in making this decision will be greatly appreciated.
Dilligara


#2

CVT s have been around a long, long time but have lacked the technology to be reliable in use in autos with larger, more powerful motors. It started with snowmobiles ( and other), small four cylinder cars and has now worked it’s way up to some models from Honda and Toyota, both of whom rely upon reliability perception as their major selling point. Personally, at this point, I would worry less about the transmission used and more about the long term reliability of the car I bought with it’s intended use. If a foucylinder from Honda is what you want and it comes with a CVT, I would buy it. If a six cylinder from Buick met my needs and it came with a 6 speed auto, I would buy it; each with no concern for transmission type.
Btw, the Accords are all CVT autos with 4 cylinder and gear autos with 6 cylinder. So, if an Accord what you want, choose between a 4 and and a 6 cylinder, and not worry about the trans reliability of either.


#3

CVTs have been around for several decades, beginning with the largely forgotten '60s era DAF automobile from The Netherlands, and then continuing with the Subaru Justy, a few decades later.

CVTs have the advantage of allowing slightly better fuel economy than conventional automatic transmissions. Their disadvantages include higher noise levels in the passenger cabin (due to a frequently high-revving engine), and the reality that they cannot currently be rebuilt or repaired in the US. CVT breakdown requires replacement of the trans, which–of course–leads to higher repair costs if the breakdown takes place after the warranty period.

When I bought my car a couple of years ago, I opted for the six-cylinder engine for several reasons, but among those reasons was the fact that the larger engine came with a conventional 5-speed automatic trans. While CVTs may well prove to be as durable as conventional automatics, “the jury is still out”, on that issue.

Incidentally, you can find CVTs on “American” cars. Some Ford models, and some Chrysler models (including some Jeeps) utilize a CVT.


#4

CVTs have been available on American cars for at least 10 years. Saturn had them as well as Ford and Chrysler products now have them.

In a nutshell, rather than having 3, 4, or 5 gears that the automatic transmission is constantly shifting through, the CVT has a “chain” that is connected to 2 sprockets, one of which can seamlessly change in size. Kind of like a bicycle, but with the rear sprocket changing diameter rather than gears. So you can go from 20mph to 60mph without the engine changing rpms. This can keep the engine running in the “sweet spot”, maximizing torque and horsepower output.

My experience is purely anecdotal with no data to back it up, but it seems I’ve seen more CVT problems on Nissans than other makes. But CVTs are very particular about fluids, and the use of the incorrect lubricant or operating low on fluid can ruin them in a matter of miles. I have customers with over 200,000 miles on a CVT, but I serviced them with the proper fluid every 30,000 miles.

For the first 30 years that cars had automatic transmissions many people preferred manuals because the automatics were more complicated and costly to repair. Any new technology takes a while to get the bugs worked out and become affordable to the masses. I think CVTs are fine and I’d buy a car I liked if it had CVT.


#5

CVT seems to go hand-in-hand with hybrids these days, to eek out those extra mpgs. Not sure how much has changed, but I think the Prius has used a CVT since its introduction in 2001


#6

There are now lots of CVTs out there. The Accord CVT is only with the 4, I think. I’d prefer a ‘regular’ automatic with a regular (non hybrid) engine. It seems the best of the CVTs (the Accord, some Nissans) are as good as a regular automatic, but there are many cases where CVT driving experience is inferior (droning, lack of response are frequent criticisms).

That said, I have a CVT in my Ford hybrid (same system at the Prius) and it doesn’t bother me. This system has no variable pulleys, no belt, no torque converter. It manipulates the output of the gas engine and two electric motors in response to the gas pedal. Works well.


#7

My 1964 Moped had a CVT transmission. I’m a little leery of them yet on cars though.


#8

@texases. Ford introduced the CVT in the Ford 500, later rechristened by Mullaly as the new Ford Taurus. It was very unpopular, especially with rental car customers who were not familiar with the sluggish performance. The “new” Taurus has a conventional transmission.

The uncertainly is not that those transmissions are not reliable; the problem is no one, not even the car manufacturers can fix them. A new replacement is very expensive and outside the warranty you are on your own.

It will take some years before you will find transmission shops that can repair and overhaul (rebuild) them. The conventional automatic went through the same development cycle.

Until that time, I don’t recommend anyone buy a car with it unless they trade when the warranty expires.


#9

Some CVT’s are better than others, Nissan has had some issues with previous CVT’s but has changed the design somewhat so we will have to see. Subaru/GM/AUDI and others have tried the idea and mostly have gone back to conventional automatics. On our trip through Ireland we rented a CVT Nissan Micra which did a much better job of staying at the right engine speed compared to the regular Automatic in the rental we used in Britain.

Certain transmissons (porsche’s PDK for example) are not supposed to be repaired by the dealership but sent back to the factory for a replacement.


#10

“Subaru/GM/AUDI and others have tried the idea and mostly have gone back to conventional automatics.”

When Subaru introduced the 4th generation Outbacks & Legacy sedan models in 2010, they began to offer a CVT with the 4-cylinder models. Subsequent to that time, they have actually expanded their CVTs to other models as well.


#11

I was watching the new car special from Motorweek on PBS yesterday. Toyota is going to a CVT in the Corolla for 2014, but instead of continuous operation, the transmission is programed to change ratios in steps, simulating a conventional transmission. Go figure.


#12

My wife “volunteered” my services in helping a family friend purchase a new car this past spring. This friend is a singe woman in her late 60s, and had determined that she wanted a Honda. We tested the 4 cylinder Accord with the CVT and the Honda Civic 4 cylinder with the regular automatic transmission. The Accord was very smooth and quiet. However, the Civic was easier to get into her garage that comes in off a narrow alley. I did toss in the fact that the Civic has a regular automatic transmission and that I wasn’t certain of the reliability of the CVT. At any rate, our friend bought the Civic and has been quite pleased.

I did drive a Nissan Sentra on a 600 mile round trip to a conference and that Sentra had the CVT. That transmission seemed to work fine. However, it was a rental vehicle, so I have no idea what kind of maintenance the transmission would need.


#13

If you were test driving new accords and one had a CVT, it wasn’t the V6. The V6 is not available with the CVT. It’s rare to see a CVT with high output engines, CVT’s typically don’t cope with higher levels of torque all that well.


#14

Whether a CVT is reliable or not depends more on the reputation of the manufacturer then the item itself. If a car maker has a history of spotty reliability ( some European makes), feel leary about any new technology. If the Accord and Corolla uses a CVT in some models who’s sales have long depended upon their perceived reliability, I would not worry. Some cars have introduced items like variable valve timing and turbo charging with less then Stella results, others have had few problems. It depends upon the maker. Fuel injection had problems with some makers early on, others, absolutely none what so ever.

I would not judge the CVT reliability performance in some cars based upon the history in others.


#15

How many CVT builders are there? I doubt that every auto builder manufactures their own.


#16

@jtsanders
But, if an auto company does not make their own, like all subcontractors, I assume like other parts and systems, they are not ALL the same when sent out to each auto maker. They are manufacturered, like most other parts and systems, to the specs given to them.


#17

Someone already mentioned it but the Ford 500 had a CVT optional. I don’t know how long that lasted.


#18

The CVT in the Ford 500 went away because Ford started putting the 3.5L engine in the car. The 3.0L was down on power compared to it’s competition, and with the CVT it just exacerbated the issue. The CVT used in the 3.0L 500’s wasn’t going to tolerate the extra torque of the 3.5L, so it went away. Even with the 3.0L engine the CVT they used was pretty close to it’s maximum torque capacity.


#19

Snowmobiles perfected the CVT concept many years ago…Some of the ones used in cars have been less than reliable…They are not “field serviceable” so if they fail, they must be replaced with a factory rebuilt or new unit. Price one for any car you are contemplating that is equipped with one…


#20

@VDC Driver, I meant to say that other than Subaru most have switched back, The corolla has a cvt with the exception of the base model with the previous 4spd auto (the cvt has 7 ratio steps according to C&D) Honda and Toyota have had better luck with CVT’s compared to Nissan