Does anyone know where to get 15w40 CI-4 without buying amsoil? I use amsoil in my 03 but I want to stick with conventional in my 98. I would love to find some valvoline premium blue classic and have emailed valvoline with no reply. I know im eventually going to probably have to switch to CJ-4 (or amsoil) but I want to put it off as long as I can.

Like Low Sulfur Diesel and Leaded Gasoline it going to become a thing of the past...

Have you considered the Amsoil semi-synthetic? https://www.amsoil.com/storefront/pco.aspx Preferred pricing is just over $21 a gallon, a little cheaper than the full syn 15w-40.

It may no longer be so, but before I changed to Valvoline Premium Blue, I could still get WallyWorld SuperTech 15W40 Dino in CI+ formulation. That oil was a good performer in my truck for over 80K miles without a complete oil change!!!

Thanks guys, looks like I may be getting back to the US in a few weeks and I will figure something out by then.