Originally Posted by Jim Hef
Why don't they just engineer a CVT that can take the torque and be done with it. All those shift points would be annoying if felt, as posted above for the Audi.
A couple reasons:
1) Not everybody likes the dynamics of a CVT. They have some advantages, but they also have some disadvantages. For example, they take a bit longer to figure out what you want to do- when you floor it, there's about half a beat before it sorts things out and pours on the power.
2) The nature of a CVT means it doesn't handle torque very well. They've been getting better at it, but the pulleys and belts are fairly vulnerable and it's easy to burn the things up or snap them entirely.
The thing is, no transmission is going to make a large displacement engine efficient. Not going to happen; they can make incremental improvements here and there, but there's no box o' cogs they can bolt on that's going to deliver great mileage. Increasing numbers of gears help, but as you say, then you're shifting a lot.
I'm expecting the real answer to be something more along the lines of what Ford has done- switch to a smaller displacement overhead cam design to generate the same amount of power. GM is still flogging their small block, but even its days are numbered. I don't see Chrysler hanging on to the 5.7L Hemi indefinitely... in fact, I fully expect that in some basement they're working on it's eventual replacement right now, and it will probably be smaller by a fair margin.