Typically these gimmicky systems are used in cars that have horrid MPG and use this as a way to mess with the stats. They get to bounce mpg up a few notches and then hope no one notices the huge asterisk beside it.
As a whole, they are gimmicky and complicated. The complex mechanical and electrical systems responsible for making them work are just one more bit of unnecessary crap that always goes bad, and this is the number one reason you don't see these on every car made.
Think about it. If the technology had actually panned out, why wouldn't you put it on every car made? Every car made spends time where it is literally wasting energy. My v8 puts out much more power than I actually need in 90% of my driving situations. Why not shut 2 or 4 cylinders down when in the city, never going faster than 35 mph? Well, because they are crap; that's why. They don't last very long and when they break they mess everything else up.
As a whole, they are gimmicky and complicated. The complex mechanical and electrical systems responsible for making them work are just one more bit of unnecessary crap that always goes bad, and this is the number one reason you don't see these on every car made.
Think about it. If the technology had actually panned out, why wouldn't you put it on every car made? Every car made spends time where it is literally wasting energy. My v8 puts out much more power than I actually need in 90% of my driving situations. Why not shut 2 or 4 cylinders down when in the city, never going faster than 35 mph? Well, because they are crap; that's why. They don't last very long and when they break they mess everything else up.
