The City of Orlando has introduced nine hydraulic hybrid refuse trucks into its vehicle fleet to lower costs and emissions from diesel-engine exhaust.

Nine new refuse trucks using Parker Hannifin's RunWise hybrid drive system headed out on Thursday to help handle the city's most demanding waste-collection shift after Christmas Day.

The hybrid trucks are expected to reduce fuel consumption by as much as 50% compared to a conventional truck using powertrains that rely on the hydraulic motor and regenerative braking until the truck reaches 45 mph.

The hydraulic hybrid system relies on hydraulic pressure to capture energy from the truck's brakes and use it to pressurize hydraulic fluid that propels the vehicle.

The trucks cost $394,000 compared with $239,000 for the existing model, and are expected to save $35,000 a year in fuel costs. The trucks will also extend the brakes, which are now replaced about every 90 days, to six years, reports the Orlando Sentinel.

The trucks will also reduce collection time by up to 10% and reduce carbon emissions by up to 48 tons per year. The trucks are expected to pay for themselves in five years, according to a city spokeswoman.