The Cascadia Natural Gas delivers near-zero emissions, and with its advanced aerodynamic design, it is both fuel efficient and environmentally friendly. On average, natural gas fuel is less expensive than diesel fuel, translating into significant fuel-cost savings for your fleet. The optimally designed hood, grille, mirrors and bumper along with upper door seal and 12 inch side extenders provide aerodynamic enhancements intended to reduce overall drag and improve fuel economy.