The 953D and 963D track loaders are powered by the Cat C6.6 ACERT Technology engine, which delivers 148 hp in the 953D and 189 hp in the 963D. When compared to the C-series models that the new track loaders replace, power is up by more than 15% in the 953D and more than 25% in the 963D. The 6-cylinder engine provides advanced electronic control, precise fuel delivery and refined air management, resulting in enhanced performance and lower emissions. Engine emissions meet Caterpillar Inc., Peoria, Ill.Tier III standards. Both track loaders feature a new load-sensing, electrohydraulic implement system.