Kenworth is now offering extended protection plans for its 2013 Paccar MX-13 engine. The 12.9-liter engine is designed to meet demands of heavy-duty trucking and is available in Kenworth Class 8 models. Extended warranty coverage options range from three to seven years and from 100,000 to 700,000 miles. The extended coverage is available when ordering the engine, purchasing a new Kenworth truck or up to 18 months following a purchase. A $400 registration fee is required for extended warranty orders placed from 13-18 months after truck purchase.