Would you pay for premium gasoline when you could save on regular unleaded?

Ward 4 Councilman Joseph Solomon thinks that’s a question the Warwick Police Department should ask when spending an estimated $550,000 to keep its fleet of 107 vehicles on the road for the year.

Solomon gave an off-the-cuff calculation at Monday’s City Council meeting that the department could save $38,000 if it used regular unleaded gasoline.

“Let’s recoup those savings,” he said. “I think it is something worthwhile looking into.”

Solomon noted that the 13 new Ford Taurus police interceptors the department recently added to its fleet have six-cylinder engines designed for regular unleaded. Also, Major Robert Nelson told the council even though the cars can use regular gasoline, the manufacturer recommends a higher premium for improved performance. He said another 13 of the new cars would be ready in April.

“This is not your grandmother’s Taurus,” Nelson said in a follow-up call Tuesday. He said the cars, which deliver 290 horsepower, are equipped with “super performance engines.”

Nelson estimated the average police cruiser uses at least a half tank of gasoline daily and logs between 28,000 and 30,000 miles a year. He said once the cruisers have put on 90,000 to 100,000 miles, which is in about three years, they are used by detectives and for other purposes.

The department has 51 marked cruisers and 25 detective cars. There are five vehicles for department administrators, 11 special vehicles, nine undercover vehicles and six motorcycles.

“They are not used and abused and thrown away. We get a lot of use out of them,” Nelson said.

He reasons that using 90-octane, or middle-grade, gas, rather than regular 87-octane gas, extends the life of the vehicle while providing better performance.

In addition to saving on maintenance, acting chief of staff William DePasquale observed that higher-octane gasoline can deliver better mileage, and that would need to be considered if the city is to accurately measure the cost-effectiveness of switching to regular unleaded.

Nelson put the price difference between the two grades at about seven cents a gallon. He estimated the department uses about 150,000 gallons a year.

“We want the cars to last long,” he said.

The oldest car in the police fleet is a 1992 Chevy van, and on average the cars remain in the police fleet for seven or eight years before being offered to another city department.

As for the purchase of gasoline, Nelson said the department has a single fueling tank and that all vehicles are using 90-octane gas. He said department gasoline purchases are tied into a daily rate and that the contract is based on a margin that is tacked on after the market cost plus any taxes.

With the dramatic drop in gasoline costs over the last six months, which has turned around in recent weeks and is heading back up, Nelson is confident the department will realize a surplus in its gas account from what was budgeted when the fiscal year closes on June 30. Nonetheless, looking ahead, he said he has heard speculation that prices will continue climbing and that as early as next year $4 per gallon gasoline will be back.

The City Council approved the $550,000 contract with Peterson Oil Service of Worcester starting this April and running for a year. A spokeswoman for Peterson said the contract is based on a “cost plus” basis that takes into account the fluctuating cost of gasoline and is “fairest” to its clients.