Do small

Small engines do not necessarily guarantee fuel efficiency. While it's true that smaller engines can often be more fuel-efficient than larger ones due to their reduced displacement and weight, several factors contribute to overall fuel efficiency beyond just engine size. Some of these factors include:
Engine Design: The design and engineering of the engine play a significant role in its fuel efficiency. Factors such as combustion efficiency, friction reduction, and overall mechanical efficiency can vary greatly between different engine designs, regardless of size.
Technological Advancements: Advances in technology, such as direct injection, turbocharging, variable valve timing, and hybridization, can significantly improve fuel efficiency regardless of engine size. These technologies are often implemented in both small and large engines to enhance efficiency.
Vehicle Weight and Aerodynamics: The weight of the vehicle and its aerodynamic properties can impact fuel efficiency. Even with a small engine, if the vehicle is heavy or has poor aerodynamics, it may still consume more fuel.
Driving Conditions and Behavior: How a vehicle is driven and the conditions in which it operates can greatly affect fuel efficiency. Aggressive driving, excessive idling, and driving in stop-and-go traffic can all reduce fuel efficiency regardless of engine size.
Fuel Type and Quality: The type and quality of fuel used can also influence fuel efficiency. Higher-quality fuels and alternative fuels may offer better efficiency, but this can vary depending on the engine's design and compatibility.
Maintenance and Tuning: Proper maintenance and tuning are crucial for maintaining optimal fuel efficiency. Regular servicing, including air filter replacement, spark plug replacement, and engine tuning, can help ensure that the engine operates efficiently regardless of its size.
While smaller engines often have the potential to be more fuel-efficient, it's essential to consider these other factors to determine the overall efficiency of a vehicle. Additionally, advancements in technology continue to narrow the efficiency gap between small and large engines, meaning that larger engines can also achieve impressive fuel efficiency under the right circumstances.