|Freightliner Chassis introduced at the first hybrid-electric Class A motorhome during December 2008. This new chassis will be available for order in the summer of 2009, with production expected to commence in the third quarter of 2009.
Equipped with Cummins ISB 6.7-liter engine with up to 300 hp and the Eaton hybrid-electric system, the new chassis - "ecoFRED" - is "so named because of its increased fuel economy and ecological/ environmental benefits." Freightliner say it has the additional benefits of significantly less brake wear due to regenerative braking, leading to lower replacement costs. It also boasts better acceleration and increased towing capacity, and operates similar to driving an automatic transmission.
Fleetwood and Winnebago have each built prototype coaches on ecoFRED and showed them at the National RV Trade Show in Kentucky in December 2008.
Bob Olson, Winnebago chairman, CEO and president added, "Winnebago Industries has a rich tradition of creating innovative fuel-efficient motorhomes, and we're pleased to have partnered with Freightliner Custom Chassis Corporation on developing the ecoFRED chassis concept used in our Winnebago Adventurer Hybrid concept vehicle." (See RoTi article - June 2009)
Olson noted, "We're also excited that our Adventurer Hybrid has the industry's first ecoFRED chassis equipped with an Auxiliary Power Generation (APG) unit that senses hybrid battery power levels and automatically engages the coach's engine to charge the batteries."
Chassis Provides Seamless Operation
ecoFRED, which features a diesel engine coupled with an electric motor/generator and lithium-ion batteries, works in line with the transmission, enabling seamless operation incorporating both electric and diesel power.
The lithium-ion batteries featured on the hybrid system capture and store energy during the regenerative braking phase of the vehicle's operation. The batteries are constantly charged through the operation of the diesel engine, eliminating the need to plug into an electrical source. Both the diesel engine and the electric motor can provide power to the drivetrain. The sophisticated hybrid supervisory controller selects the most efficient mode of operation ¿ diesel, electric or both ¿ depending upon current operating conditions and driver demand.
Additionally with ecoFRED, motorcoach travel is not limited by unique fuel requirements or the need for special refueling locations as compared with other alternative power train vehicles.
ecoFRED also requires less braking because of its regenerative braking system, resulting in less brake wear and an extended brake life. Regenerative braking means that the HEV electric motor uses electricity to create torque, while also being able to reverse the process to use torque to create electricity. By reversing its electric motor to become a generator, electricity is fed back into the batteries, resulting in energy savings.
Another added benefit of ecoFRED is increased towing capacity with a gross vehicle weight rating (GVWR) of 27,000 lbs. and a gross combined weight rating (GCWR) of 37,000 lbs. This enables travelers to carry more weight in the coach storage compartments or tow a heavier or additional vehicle.
Understanding the importance of maneuverability to motorhome owners as they travel and navigate through tight spatial constraints, FCCC engineers also designed ecoFRED to offer a best-in-class 55-degree wheel cut.
"Maneuverability is always a challenge for motorhome owners," said Tony Sippel, FCCC RV product manager. "Turning corners and entering and exiting parking areas can be difficult when operating a large vehicle. We incorporated a 55-degree wheel cut similar to the FRED chassis into the design of ecoFRED to allow drivers to more effectively navigate roadways, campgrounds and parking lots."
Also similar to the FRED chassis, ecoFRED does not have an engine hump or "dog house" typically found on a gas chassis. The result is a flat floor and more room in the driver cockpit, contributing to driver comfort and easier entry and egress from the seats to the back of the motorhome.
An idle-off feature will be available on ecoFRED in the near future. Idle-off enables the engine to shut down while sitting idle at traffic lights or while in traffic. This saves fuel by reducing engine idle time. The engine will shut off automatically after three to five motionless seconds. As soon as the driver removes pressure from the brake pedal, the engine will resume and normal driving conditions will apply."