I was in an auto parts store today and i heard a parts clerk answering a customers question the customer asked what oil and filter for his 2008 Camry the customer said he used synthetic but wanted conventional because he wanted to save money..The clerk said to him in an alarming voice that if he used conventional after using synthetic his engine would seize up and handed him some castrol snthetic 10w30 and a fram filter..I had a hard time controlling myself so i asked the parts guy what causes the engine to seize up using conventional and he said he was suprised that me being in the engine business never heard of this...He explained to me that conventional is watered down and causes a sandpaper like effect on the pistons... I handed him a paper with the B.I.T.O.G. website and told him to go there and read up on his theory and next time i come back i want to discuss this further.. It's people like this that makes life interesting.