Orics,
The Amsoil 0w-30/5w-30/10w-30, 100% synthetics are all being formulated a bit thinner than before - specifically to meet the Energy Conserving requirements of API/SM and GF-4. They are now ACEA A5/B5 rated oils and also meet the even more stringent VW 503.00 "Longlife" specification, which allows 30,000km/2 yr OCI's in specific VW/Audi engines. VW 503.00 requires HT/HS viscosities > 2.9 Cp and < 3.5 Cp @ 150C. The 5w-30/10w-30 come in @ 3.2 Cp @ 150C.
I see no issues running the slightly thinner Amsoil 5w-30 in this application, especially in the winter when oil sump temps will be quite low.
As an aside, Amsoil has a habit of using up all their old product labels before printing new ones. The latest specs for their 5w-30 and 10w-30 are posted on their website. The spec sheet for the Series 2000 has yet to be updated, but it's now 10.5 Cst @ 100C, with a HT/HS viscosity of 3.3 Cp and a VI of 187.
Hope this helps!
TS