What Causes the Engine to Sound Louder When Driving in Winter?

[JohnLynn]

When driving in winter, the engine sounds louder because the engine needs to reach its optimal operating temperature and power various equipment, which requires a larger throttle opening, resulting in increased engine noise. Once the equipment operates normally and the engine reaches its standard temperature, the throttle opening decreases, and the noise reduces accordingly. Vehicles equipped with turbocharged engines tend to produce even louder noises during cold starts. To minimize engine noise, a dual-spring fuel injection valve can be employed to achieve pre-injection. This method splits the fuel intended for a single cycle into two injections: a small portion is injected first, initiating a pre-reaction before the main injection. This reduces the amount of combustible mixture accumulated during the ignition delay period, effectively lowering combustion noise in direct-injection diesel engines.