I agree, it's a completely useless way of saving petrol as well. Someone posted last week that one single thing that would make all the difference would be 24hr power supply and that would eliminate the need for people to buy additional gas for generators, which must make up a significant percentage of fuel sales, diesel anyway.
I would not complain too much if I could choose one, or even two days in the week when my car was off the road, which I do anyway, but I can see how this would be a problem for many people.