By Doug Fletcher,Staff Writer

Topping off the gas tank will be a bit costlier today – 0.7 cents per gallon more, to be exact.

Maine’s excise tax on gasoline rose to 25.9 cents a gallon at 12:01 a.m. That’s because the tax is tied to inflation, with any adjustment taking effect at the start of the state’s fiscal year on July 1.

That 0.7-cent increase is expected to generate $4 million to $5 million for the state treasury.

Maine decided to index its gasoline tax to inflation in 2001. Bills to repeal the indexing failed in 2004.

Since the law took effect, the tax has increased by varying amounts depending on the consumer price index. Last year, it went up 2.5 cents. A year earlier, it was 0.6 cents, although most pump prices were upped a penny.

The gas tax is used to pay for highway improvement projects – everything from new bridges to filling potholes on secondary state roads.