Anyone speeding though Pratt County will likely see a new 2013 sheriff's patrol car catching up to him or her in the rear view mirror.

The Pratt County Sheriff's office is upgrading their vehicle fleet as part of their regular three-vehicle a year rotation program. Sheriff's office vehicles are rotated out of service after every 100,000 miles. That usually happens after the vehicle has been in service for three years.

Rotating vehicles on a regular 100,000-mile basis helps the sheriff's office avoid high maintenance costs. In the past, vehicles were kept for 200,000 miles but the maintenance costs were high. Then vehicles were kept to 150,000 miles but maintenance costs were still high so vehicles are rotated out at 100,000 miles now.

"It saves us a lot of money," said Pratt County Sheriff Vernon Chinn.

Rotating vehicles at 100,000 is also safer for officers on patrol and for residents when they are responding to an emergency call. The vehicles are much less likely to break down.

Coming on the fleet is 2013 Chevrolet Tahoe and a pair of 2013 Dodge Chargers. The Tahoe and one Charger were purchased in May and the second Charger is scheduled for pick up in the first week in December, Chinn said.

The first Charger is in the process of being outfitted.

Vehicles are purchased through a state bid at a substantial savings to the sheriff's office. The state guarantees certain dealers they will purchase a certain number of vehicles. Those vehicles are sold on bid to sheriff's offices across the state. The newest vehicle was purchased for $23,500 but was list for $33,900, Chinn said.

These vehicles come as stock and need modification before they are put into service. The purchase prices is about two thirds of the total cost of ready-for-service vehicle. It costs about $10,000 to install the necessary equipment.

Vehicles are outfitted through Southern Police Equipment. Sheriff's offices get credit on equipment on trade-in vehicles.

Each vehicle has to have a light bar and three radios, one for VHF, one for UHF and one for the 800-band width for the state. Each vehicle also has to have a lap top computer for each deputy.

With the ever-changing technology, the computers in the vehicles have to be updated every three years.

The light bars also wear out and they have to be changed out on a regular basis. Light bars run about $2,000 apiece.

As much as possible, the sheriff's office purchases equipment locally to keep vehicles outfitted. Currently, they spend about 75 percent of the budget locally. Cooper Tire of Pratt is a local vendor for state bids.

Light bars now use LED lights that are much more efficient and save energy. With the old style lights, an idling vehicle could run down the battery and wear out an alternator. They were much less expensive at $300 but the ate up the amperage, Chinn said.