ICBC Driving Commercial Vehicles Practice Exam 2025 - Free Commercial Vehicles Driving Practice Questions and Study Guide

In cold temperatures, allowing a diesel engine to idle for 7-10 minutes after starting is essential for several reasons. Diesel engines require sufficient time to warm up, especially when the temperature is low. During this initial idling period, the engine oil and the coolant can circulate, ensuring that all components of the engine reach an optimal operating temperature.

When the engine is cold, the oil may not flow easily, and its viscosity can affect lubrication, potentially leading to increased wear and tear on the engine components. Additionally, the fuel may not be combusting as efficiently until the engine warms up, which can contribute to issues like higher emissions and increased fuel consumption.

Moreover, modern diesel engines are designed with turbochargers, and allowing adequate warming time helps the turbo system to function correctly and increases the overall lifespan of the engine. Therefore, idling for a longer duration, like 7-10 minutes, is a good practice to ensure the engine runs smoothly and efficiently in cold conditions. This approach helps prevent potential damage and promotes optimal performance as the engine transitions to normal operating conditions.