Why is there typically more fluid in the left hydraulic reservoir than in the right?

The left hydraulic reservoir typically has more fluid because the gear movement on the left side of the system requires a greater volume of hydraulic fluid to operate effectively. In many aircraft designs, the left hydraulic system is responsible for powering critical flight control surfaces, landing gear, and other vital components that demand higher fluid capacity due to their mechanical work requirements. This higher demand leads to the left reservoir containing more fluid to ensure reliable operation and accommodate the needs of these systems during flight.

The other options do not accurately reflect the reasons for the difference in fluid levels. Gravity feeding preferentially from one side does not usually apply to hydraulic systems that are designed to maintain equal pressure and fluid levels. While the maintenance checks frequent on one side could slightly affect fluid levels, it is not a standard factor contributing to the operational design or fluid capacity discrepancies. Lastly, the left system having a larger capacity could hypothetically lead to higher fluid levels, but the primary operational demands of gear movement and hydraulic necessity dictate the volume of fluid maintained.