Well I beg to disagree. One of the hardest tasks on oil is containing and neutralizing acids and moisture, both of which the Volt ICE is much more prone to produce from its style of infrequent running, stop-start, etc. Top-tier full synthetic for me. My weapon of choice is Amsoil Signature Series 5w-30. For a 2- year change interval, the price is insignificant to me.