AUGUSTA, Maine — For two decades, the basic patrol vehicle of law enforcement agencies across the state has been the Ford Crown Victoria police interceptor, but the last one rolls off the assembly line next month, and agencies are scrambling to find a new vehicle. They have found all of the options are more expensive.

Crown Victorias “served us really well,” Penobscot County Sheriff Glenn Ross said. “We are watching to see what is coming out, but we will not be the first to buy. We are good for the short term.”

Ross, president of the Maine Sheriffs’ Association, said all of law enforcement is struggling to replace a vehicle big enough to handle all of the additional equipment needed in a police cruiser that can be maintained with reasonable costs. He said the typical cruiser will have communications equipment, both a radio and a data terminal and lots of other gear.

“We also, in a rural area like this county, carry a lot of equipment we might need, and that pretty much fills the trunk,” Ross said. “We all really look at what it costs to keep a vehicle on the road, fuel efficiency, what it needs for routine maintenance.”

That, he said, is where agencies are left guessing, because all of the potential replacement vehicles have no track record. Ford is offering its Ford Police Interceptor based on its Taurus model. Chevrolet is offering an Australian-made version of the Caprice, different from the one made in the United States. Chrysler is offering a version of the Dodge Charger. A startup company, Indiana-based Carbon Motors, is offering a diesel-powered police car that is drawing some interest.

Nationally, about 75,000 vehicles a year are purchased by law enforcement, and about two-thirds of them have been Crown Victorias. Agencies also buy specialized vehicles for undercover work, and four-wheel-drive pickups are used by many rural agencies.

“We have looked at what is out there and we are looking at the Dodge Charger,” said South Portland Police Chief Ed Googins, president of the Maine Chiefs of Police Association. “We like their construction, the full frame is safer, and it is the only one out there that is full-frame like the Crown Vic.”

He said it is also a rear-wheel-drive vehicle and that should mean better gas mileage and lower maintenance costs. He agrees with Ross that a “big unknown” is the cost to maintain the vehicles, a concern for police agencies facing flat or reduced budgets.

All are concerned about cost. A basic Crown Victoria has been selling for around $25,000. Police agencies are looking at vehicles in the $28,000-$30,000 range as replacement patrol cars.

“Cost is going to be a big consideration for a lot of departments,” Ross said.

Googins said departments may take the opportunity to explore other options. He said his agency has a Chevrolet Tahoe SUV that gets better mileage than its patrol cars because it has technology to reduce the number of cylinders in use while the motor is idling.

“We do a lot of idling,” he said. “It also provides us with a lot of room for equipment, and we are carrying a lot more equipment than we used to.”

Googins said a lot of police agencies are using vehicles longer than they used to. He said many are keeping vehicles in use for 125,000 miles and some longer. Ross said he plans to keep the three or four new vehicles his department will buy this year sitting on the lot until a patrol car has to be replaced.

“We have to make everything last longer,” he said.

Col. Robert Williams, chief of the Maine State Police, said his agency has all but finally settled on the new Ford Interceptor. He said troopers and staff have taken test drives of the top contenders and believe the Ford, in the all-wheel-drive model, is the best choice for state police.

“We decided a few years ago to buy the vehicle that best fits the need,” he said. “That’s why we have some SUVs in the fleet and some other specialty vehicles. But for a general patrol vehicle right now, unless something happens we are leaning to get the Ford vehicle, the all-wheel-drive model.”

Williams shares the concern of buying the first model of any vehicle, but he said state police replace about 50 cars a year and cannot push the existing cars beyond 125,000 miles while the cars develop a track record to review.

“The problem with running your vehicles that long isn’t that the engines and drive trains won’t go that long, it’s that the steering becomes loose,” he said. “When you drive at high speeds and you go into a curve, a hundredth of an inch on a steering wheel can be 3 or 4 feet.”

While no one keeps numbers, law enforcement agencies of all types in Maine are expected to buy several hundred vehicles this year.