Won't work unless you decide to sell your car

Filling it up with gas before the weekend doesn't put any less $$$ in the oil company's pockets.
Plus, gas in the US is still a bargain compared to most other industrialized nations. We complain but it could be SO much worse. It's STILL not as expensive as it was in the 80's.
And it's already been thought of before - and debunked:
http://www.snopes.com/politics/business/nogas.asp
Sorry
