Saw your "five myths" post. The thing is that the big issue isn't how much you drive, but mileage. And there's a strong effect of prices on consumption, mainly through that channel.
Oh, you do have to be careful, though: Europe uses a lot more diesel, so you don't want to just look at gasoline.
Here's the figure for use in the 2nd edition of the Krugman/Wells text showing that higher fuel prices are associated with lower fuel consumption: