Engine Oil: Inspection

Park the vehicle on a level surface.
Remove the oil level gauge and wipe it clean.
Reinsert the level gauge all the way. Be sure that the level gauge is correctly inserted and properly orientated.
Remove it again and check the reading. If the engine oil level is below "L" line, add oil to bring the level up to "F" line.
After turning off the engine, wait a few minutes for the oil to return to the oil pan before checking the level.
NOTE:
To prevent overfilling of engine oil, do not add oil above "F" line when the engine is cold.

Fig 1: Identifying Engine Oil Filler Cap And Oil Level Gauge Range Line (F And L)
Courtesy of SUBARU OF AMERICA, INC.