Classic/Antique Car Repair: QUESTION MOTOR OIL

Question
Brad, hi can you please tell me what oil car owners are using in the cars from the 20's. Would you use synthetic if the car sits in a garage. For many years I was told to use Non Detergent, for many reasons. Please let me know, thank you Ken

Answer
This is one of those questions that goes not have one set answer. If the engine is mostly original and has not been rebuilt back to close tolrances then I would use a 30W with an API rating of at least SD. The API ratings are found on a circle on the oil container any run from SA
Down the alphabet with SA being the poorest grade. If the engine is a recent rebuild to close tolerances then I would use an oil with at least SD  but a viscosity rating of 10W/30. I my self would not use synthetic oil. As far as detergent goes I would not hesitate using it as the non detergent oils are only found in the SA thru SC API rated oils and truth be told these are great oils or sewing machines and Junior's tricilce  but not in a heat developing internal combustion engine.