The Pilot's Operating Handbook for the Cessna models 152, and 172N Skyhawk have the following information concerning the engine oil:
"Capacity of Engine Sump - 6 quarts. Do not operate on less than 4 quarts. To minimize loss of oil through breather, fill to 5 quart level for normal flights of less than 3 hours. For extended flight, fill to 6 quarts. These quantities refer to oil dipstick level readings. During oil and oil filter changes, one additional quart is required when the filter is changed."
The Pilot's Operating Handbook for the Piper PA-44-180 Seminole states as follows concerning oil requirements:
"The oil capacity of the Lycoming engines is 6 quarts per engine with a minimum safe quantity of 2 quarts per engine. It is necessary that oil be maintained at full (6 quarts) for maximum endurance flights."
The phrase_"a minimum safe quantity of 2 quarts per engine"_should be explained. If the operator checked oil after a flight and found less than 2 quarts in the engine, it is quite probable that engine damage has resulted. No flight should be started with only 2 quarts of oil in the sump.
Pilots and mechanics should not confuse the models just discussed with other Lycoming four cylinder, wet sump engines that hold a maximum of 8 quarts of oil. There is no change in our recommendations when checking oil for the latter. During normal routine flying, oil levels are best maintained at the 6 to 7 quart level.
