Hartford — With gas prices ascending beyond the $4-per-gallon mark, Gov. Dannel P. Malloy signed into law Tuesday a bill that could start saving motorists 1.7 cents a gallon beginning today.

The new law puts a cap on the state’s petroleum gross receipts tax. This tax, which carries an effective rate of 7.53 percent, is paid by fuel distributors based on the wholesale cost of fuel, but gets passed along to gas stations and then to motorists.

The tax is now capped at the wholesale price of $3 per gallon, which means it will stay at 22.5 cents per gallon unless gas prices fall. The wholesale price was $3.29 Monday at New Haven Harbor, a 6.6 cent jump from Sunday.

“The best we can say today is that the price of wholesale gasoline will not increase by 1.7 cents and 6.6 cents together,” Eugene Guilford Jr., president of the Independent Connecticut Petroleum Association, said in a statement.

The General Assembly passed the tax cap legislation last week with unanimous votes in both chambers. The act also includes a series of measures aimed at preventing and penalizing price gouging.

Lawmakers left alone the state’s other tax on gasoline — a flat 25 cents per gallon. Motorists also pay 18.4 cents per gallon in federal taxes.

A gallon of regular, unleaded fuel in Connecticut costs an average of $4.09, according to the Daily Fuel Gauge Report operated by AAA. The national average is $3.92.