How have modern manufacturers designed smaller engines to meet demands of once larger engines?

Modern manufacturers have focused on increasing volumetric efficiency in smaller engines to meet the performance demands that were once only achievable with larger engines. Volumetric efficiency refers to the engine's ability to fill its cylinders with air (and fuel) during the intake stroke. By maximizing this efficiency, manufacturers can ensure that smaller engines can produce more power without needing to increase their size.

Improvements in volumetric efficiency can be achieved through various means, such as optimizing the design of the intake and exhaust systems, implementing advanced turbocharging techniques, and using variable valve timing systems. These innovations allow smaller engines to draw in a greater amount of air and fuel mixture, resulting in improved combustion efficiency and power output.

While other options such as increasing engine speed or enhancing fuel quality can contribute to performance, the fundamental shift in capability for smaller engines largely comes from advancements in volumetric efficiency, enabling these engines to deliver power levels comparable to those of larger, traditional engines.