If it says 1, it is 1. If it says 1 plus Gen 2 then it is Dexos 1 gen 2. If it says 2 then it is Dexos 2. Dexos 1 being obsolete means they are now making Dexos 1 Gen 2 and maybe not Dexos 1 anymore. But the supply of Dexos 1 NON-Gen 2 is there but will drop o... Login to read more.