Auxiliary Power Dynamics offers the Willis APU, a professional-grade auxiliary power unit engineered for a Class 8 truck.The Willis APU dramatically reduces idling by providing power as soon as the truck is parked. An optional air compressor can help owner-operators avoid costly downtime. Customers report payoffs in as little as 16 months from fuel savings and downtime avoidance. Fully integrated into the truck, the Willis APU delivers more heating and cooling capacity than other APUs. Its three-cylinder, 18-hp Kubota engine makes it quieter, more powerful and less expensive to maintain.