It would be possible to have an "8 speed CVT". The Audi CVT can be shifted similar to an automatic transmission that allows you to select gears on the fly. The Audi is programmed with 5 shift points, to sorta be like 5 gears, so you put in the right spot and its in low or one of several mediums or high. Mostly however, you put that sucker in D and let the computer do the work for you.
There are actually four of the "conical cogs" as it was put. The are arranged like this:
-->-<-- from engine
| |
| |
| |
-->-<-- to wheels
where the > and < are the cogs the || is a belt and the - are shafts. The cogs can move closer together or farther away on the shafts, which affectively changes the size of the "gear". If its closer, than the belt has to go around a circumferencially larger circle, if they are farther away, the belt wraps around the narrower part and is effectively on a smaller gear, i.e.:
---><--
| |
| | cogs close together
| |
---><--
->--<-
| |
| | cogs far apart
| |
->--<-
By having the shaft from the engine being small, and the shaft to the wheels large, the wheels can turn slower but with more power for acceleration. When the shaft from the engine is large and the shaft to the wheels is small, then the wheel can turn faster but with less power, i.e. cruising.
--><-- engine
| |
| | acceleration
| |
->--<- wheels
->--<- engine
| |
| | highway speeds
| |
--><-- wheels
EDIT: For some reason the "belts" are refusing to center on my "cogs", deal with it.