I ordered some Amsoil product for my new motorcycle and got the preferred members package so I can save money on future oil purchases since I have 3 vehicles that'll be using oil. Anywho, I decided I'd look to see what it'd cost to get Amsoil in my 06 CL55 AMG. I also have a 99 E300TD. I was using LiquiMoly 0w40 in the E300, and 5w40 in the AMG, but since FCP Euro never seemed to have the 0w40 oil change package anymore like they used to, I switched the E300 over to the same 5w40 the AMG was getting.

I noticed the Amsoil Euro formula now meets the MB 229.5 spec, but I thought I remembered seeing they didn't have that rating before. Anyways, I'm interested in using Amsoil because I always used it in my 300ZXTT, it's going in my bike, and I like keeping everything the same. Looking at the oils, Amsoil charges more for the 0w40 than the 5w40, and looking at a part of their page, they say the 0w40 is EFO while the 5w40 is EFM. Both oils meet 229.5

In summary, 0w40 is $13.19 a quart and EFO, but 5w40 is $10.79 a quart and EFM...is there any reason to use the more expensive 0w40 when both of my Benzs have been getting LiquiMoly 5w40 already? Is there a significant difference in the two formulas that dictate a higher price from 1 formula to the next?