[RC2]

If everyone started driving more efficient vehicles, I would bet the gas prices would go higher. Gas companies need to keep their profit margins up. If they sell less gas, they will charge more for what they do sell and the same would go for the taxes on the gas. The government will not lose money just because less gas is sold.

[Michael Barnes]

The government will not lose money just because less gas is sold.

No. The Gov't will simply raise a new tax on the efficient vehicles like is already being discussed for hybrid's.