Dexos is a oil specification and a GM owned trademark. Just about every oil company has an oil that meets dexos1. The ones that pay GM get to put the dexos logo on their label (pay to play). But GM no longer specifies synthetic oil, they just say use oil meeting the dexos1 spec. According to GM, dexos1 spec superceeds all previous oil spec’s.
The reason you pay more for dexos1 is because GM gets a percentage of the oil companies sales for allowing them to use the dexos logo on their oil containers. GM is making millions of $$ of the oil you buy with a dexos logo on it.
The 3.0L is no different than all the other GM engines when it comes to oil requirements. That does not mean you cannot use a synthetic oil. It use nothing but synthetic oil and GM does not make any money from the brand I use.
