The most common grease has an NLGI viscosity of 2. I haven't been able to find any NLGI 00 grease, so this afternoon I was trying to thin down some NLGI 2 grease with Walmart SAE 30 oil. I was absolutely amazed by how much oil it takes to thin down grease. You almost have to mix it 50/50 to get it freed up. I'm trying to make NLGI 00 grease when I actually have never seen NLGI 00 grease. All I've heard is that it's closer to an apple sauce consistency.