Originally posted by shawmutt
Why?
synthetics act as tho they are thinner than their standard oil counterparts, so the have the tenedency to "find" cracks and therefore are morelikely to burn in a loose engines
If the vehicle is equipped with an AMSOIL Oil Filter, the filter should be changed at 12,500-mile or six-month intervals (whichever comes first) in gasoline engines and 7,000-mile or six-month intervals (whichever comes first) in diesel engines. Non-AMSOIL oil filters should be changed at the engine manufacturer's recommended filter change intervals
(taken from the amsoil website)