The perception of engine sound can be influenced by various factors, including the design and configuration of the engine, exhaust system, and the overall vehicle acoustics. Here are a few reasons why car engines may sound different from motorcycle engines at the same RPM:
Engine design: Car engines and motorcycle engines often have different designs and configurations. Car engines commonly have multiple cylinders arranged in a variety of configurations (such as inline, V-shaped, or horizontally opposed), while motorcycles usually have fewer cylinders (ranging from single-cylinder to inline-four configurations). The number of cylinders and their arrangement can affect the firing intervals and the overall sound characteristics of the engine.
Exhaust system: The design and tuning of the exhaust system play a significant role in the sound produced by the engine. Car exhaust systems are typically larger and incorporate mufflers and resonators to reduce noise and meet sound regulations. Motorcycle exhaust systems tend to be smaller and may have less sound-deadening material, resulting in a louder and more noticeable exhaust note.
Vehicle acoustics: The overall design and construction of the vehicle can influence how the engine sound is perceived. Cars are typically larger and more insulated, which can dampen and muffle the engine noise. Motorcycles, on the other hand, lack the same level of insulation and often have exposed engines, resulting in a more direct and pronounced engine sound.
RPM range: The RPM range at which engines produce peak power and torque can differ between cars and motorcycles. Motorcycles, particularly sport bikes, often have higher revving engines designed to operate at higher RPMs to maximize power output. Car engines, especially those designed for everyday use, may have lower RPM ranges where they produce their peak power, resulting in a different sound perception at the same RPM.
It's important to note that these are general observations, and specific engine and vehicle characteristics can vary greatly. Additionally, individual preferences for engine sound can vary, and what may be perceived as more appealing or high-revving can be subjective.