Automated Transmission In Dodge Van Test By Car And Driver

[CrimsonEclipse]

The CVT transmission relies on friction to transfer the force and many of them have to have water cooling in order to get rid of the heat from the friction. Similar with the traditional Automatic transmission. Heat is waste energy. The Automatic Manual transmission has helical gears which are more efficient at transferring rotational force. The CVT is nice in that it can maximize the motor efficiency, but as a transmission it is not more efficient.

While true, the CVT in and of itself is NOT more efficient than and AMT, a car with a CVT optimized the engine RPM for the situation and more than makes up for the slight loss in transmission efficiency and makes the entire system more efficient, which is the point.

 

[pistonboy]

As I understand, a CVT has far fewer parts than a traditional transmission. (I count the chain as one part.)

Why are they about the same price as a traditional transmission?

 

[CrimsonEclipse]

As I understand, a CVT has far fewer parts than a traditional transmission. (I count the chain as one part.)

Why are they about the same price as a traditional transmission?

Economies of scale. Standard transmissions don't sell commonly in the USA for a few reasons.
Also, with fewer moving parts comes lower cost, fewer assembly stations and shorter assembly lines (thus fewer technicians needed to build and so on)

I know of at least 2 manufacturers that offer the CVT as the base options.

Reliability is not a solid data point in my mind yet. I've seen Prius CVT's go 300k without issue but observed Nissan CVT's have problems at 60-100k in the earlier models.

Since the CVT is better suited for light vehicles and less suited for high torque (trucks) and high performance (sports cars), the Elio would be the PERFECT candidate for a CVT.

(after a year or two of production of course)

 

[wizard of ahs]

Economies of scale. Standard transmissions don't sell commonly in the USA for a few reasons.
Also, with fewer moving parts comes lower cost, fewer assembly stations and shorter assembly lines (thus fewer technicians needed to build and so on)

I know of at least 2 manufacturers that offer the CVT as the base options.

Reliability is not a solid data point in my mind yet. I've seen Prius CVT's go 300k without issue but observed Nissan CVT's have problems at 60-100k in the earlier models.

Since the CVT is better suited for light vehicles and less suited for high torque (trucks) and high performance (sports cars), the Elio would be the PERFECT candidate for a CVT.

(after a year or two of production of course)

You can put a CVT in them AFTER I get mine

 

[MrWhsprs]

Reliability is not a solid data point in my mind yet. I've seen Prius CVT's go 300k without issue but observed Nissan CVT's have problems at 60-100k in the earlier models.

To clarify, the "CVT" in the Prius (and the Ford Escape Hybrid) is a power-split transaxle with a planetary gearset, not at all a traditional belt/chain/pulley type as one might think of when hearing the term CVT.

 

[CrimsonEclipse]

To clarify, the "CVT" in the Prius (and the Ford Escape Hybrid) is a power-split transaxle with a planetary gearset, not at all a traditional belt/chain/pulley type as one might think of when hearing the term CVT.

If I'm not mistaken (it's been a while so my memory might be a tad fuzzy)
But the early Prisuses (Prii?) used a belt. The second and third used the power split planetary gear set.
And it's (the second and third gen) an AMAZING configuration. It always impresses me at the innovation of Toyota.

(full disclosure, Although Toyota impresses me with a few technology advances, they have become myopic with their overall design decisions and have become a lesser company in the last few years)

 

[pistonboy]

This website has a good diagram of a power split planetary gear set.
Place the mouse on the dots and move them.

http://eahart.com/prius/psd/

 

[WilliamH]

If I'm not mistaken (it's been a while so my memory might be a tad fuzzy)
But the early Prisuses (Prii?) used a belt. The second and third used the power split planetary gear set.
And it's (the second and third gen) an AMAZING configuration. It always impresses me at the innovation of Toyota.

(full disclosure, Although Toyota impresses me with a few technology advances, they have become myopic with their overall design decisions and have become a lesser company in the last few years)

The only CVT I've ever used is in something like a Polaris Ranger Diesel and that hesitation as it starts moving has almost hurt us as we used them to move feed trailers around.

...."A belt-driven design offers approximately 88% efficiency,[1] which, while lower than that of a manual transmission, can be offset by lower production cost and by enabling the engine to run at its most efficient speed for a range of output speeds.".... (extract from Wiki ... [ https://en.wikipedia.org/wiki/Continuously_variable_transmission ]

So just my view, if it's like the CVT in the Ranger I don't want anything to do with it.

 

[CrimsonEclipse]

The only CVT I've ever used is in something like a Polaris Ranger Diesel and that hesitation as it starts moving has almost hurt us as we used them to move feed trailers around.

...."A belt-driven design offers approximately 88% efficiency,[1] which, while lower than that of a manual transmission, can be offset by lower production cost and by enabling the engine to run at its most efficient speed for a range of output speeds.".... (extract from Wiki ... [ https://en.wikipedia.org/wiki/Continuously_variable_transmission ]

So just my view, if it's like the CVT in the Ranger I don't want anything to do with it.

From what I gather, the Polaris Ranger uses a scaled up version of the golf cart belt transmission which uses fly wheels for speed control. It's really not a good comparison to the computer controlled CVT in most cars.

 

[WilliamH]

From what I gather, the Polaris Ranger uses a scaled up version of the golf cart belt transmission which uses fly wheels for speed control. It's really not a good comparison to the computer controlled CVT in most cars.

All I can go on is the type of CVT I have experience with. And based on that experience I don't want to try it in a highway vehicle.