The source provides an extensive guide on why vehicles often struggle to start in freezing temperatures, identifying multiple mechanical and environmental factors contributing to the issue. The discussion highlights the car battery as the primary suspect, explaining how cold significantly diminishes its capacity and efficiency. Furthermore, the episode details the impact of increased engine oil viscosity, which forces the starter motor to work harder, and addresses fuel system challenges, such as fuel line freezing and poor gasoline vaporization. Finally, the source offers preventive maintenance tips for each component, including using low-viscosity oil, testing batteries annually, and employing block heaters in extremely cold climates.