eyeguy

Audi has been introducing the CVT now in the A4 and the acceleration seems worse than a traditional tranny. Shouldn't a CVT theoretically have better performance? With a CVT the engine rpm's are constant and the tranny ratios change right? Therefore, can't the engine always be at peak torque/hp and the tranny change as opposed to the tranny being constant and the engine spooling up?

I admittedly have a limited understanding of CVT's so please show me my flawed logic. Thanks.

Nashua_Night_Hawk

What I know is that the CVT is more efficent than Auto but less than stick shift...

If perfected I did not mind one... But I still prefer to have and SMG... just for handing.. remeber u use gear while cornering and as Engine braking too....

CVT does not give you thoss features...

Chung S

heres a little write up that Edmunds did, if you want to read it.

http://www.edmunds.com/news/innovati...6/article.html

EricL

The idea is to optimize the torque (and thus acceleration) to the road. In general, the idea is to stay on the power (HP) peak to accomplish this. However, there are some issues going on that "can be settled" by just stating that the "torque to the wheels" is what needs to be optimized -- and a CVT does a good job of this.

I must have been reading different articles and magazines, since the CVT has better performance when used in full auto (not with fixed ratios).

In a "conventional" manual or automatic, the gear ratios are fixed. There is a limited amount of "ratio" change via torque conversion (in a "slushbox"), but this gets a bit more involved and the losses are pretty steep in most of the torque converter driven automatics.

The CVT is similar to a manual in that it has a clutch that operates very much like a manual gearbox. It is either engaged or disengaged (unlike a torque converter that is always engaged).

CVTs are banned from Formula 1 racing and it's NOT because they cause crashes or break too often (they do offer an unfair advantage!) Enough said?

jimcol711

the new saturn VUE sport utility has a tranny like that, GM is usuing the saturn VUE as a test vehicle and will probably incorporate a CVT tranny into many future vehicles

t-rd

Performs worse? Hun? Did you look at the 0-60 numbers of Audi A4 with CVT? It is the CVT advantage that gives it that low number even with a lower HP rating. When it full auto mode, it shifts faster than a skilled manual driver. I think it was the last issue of Car and Driver they had this review on a few cars. If I recall, the TL-S with 260HP posted a lower 0-60 number than Audi A4 CVT with only 220HP.