The 621F and 721F feature four programmable power modes that allow users to match the machine output to available engine power. The loaders include heavy-duty axles with auto-locking front and open rear differentials for optimal traction in a range of conditions. The axle is designed to help reduce tire wear, especially on hard surfaces, according to the OEM. The 621F and 721F offer an optional Efficiency Package that includes a five-speed transmission with lock-up torque converter for faster road travel speed, acceleration and shorter cycle times, as well as axles with auto locking differential and advanced system programming. The optional five-speed transmission includes the Case Powerinch feature that lets operators approach targets quickly and precisely regardless of engine speed. Case says this feature ensures there is no rollback even on steep slopes, making it easier and quicker to dump into a truck.