Patman
Staff member
I have heard that as well, and I think it was true in the past, but not quite so much now. I seem to recall when I first started using Mobil 1 (and Amsoil for that matter) that they claimed they had ZERO VI improvers in their 5w30 and 10w30 oils. I don't believe this is true now, I think the 5w30s have a bit more than they'd like us to believe. I base this on the fact that I too have seen a lot of 5w30 oil analysis reports where it has thinned out to 5w20. I've seen it happen with Mobil 1 as quickly as 2300 miles!quote:
Originally posted by Scott in WI:
I've read in a number of places that "true" synthetics use very little (if any) VII's for XW-30 viscosities. IF this is the case wouldn't we be better off using using the lowest viscosity "true" synthetic?