I've noticed that several of the 5w40 dexos 2 oils have decided not to renew their dexos 2 license. Both Valvoline and Castrol have discontinued using the dexos 2 certification. Anyone have any ideas on a 5w40 oil to use that isn't terribly expensive? I sure would've preferred a dexos 2 oil but that is looking to be more and more of an issue. I've always ran the 5w30 but I'm wanting to switch just for insurance in keeping the diesel from hopefully having any issues in the future.