V@100c of the factory fill (G52) in my 2004 Golf TDI 5-speed after 43,000 miles was 6.4.
The CAT lab ran the viscosity test twice because I listed the oil as being a 75w-90 - which G52 clearly is not.
I had the lab perform a VOA on the Motul Gear 300 I put in and its V@100c = 14.0.
My thinking was that either the OEM oil sheared way down OR the OEM fluid started out much lighter than the 75w-90 oils that many of us are commonly replacing G52 with.
So, I went to the dealer this morning, bought a liter of G52, then drove to my local CAT fluid analysis lab and watched as he tested its viscosity right in front of me.
The result: VOA viscosity of G52 = 6.3
Viscosity Comparison @ 100 C
10.6 = Redline MTL 70-80
13.8 = Amsoil MTG 75-90
15.2 = Motul Gear 300 75-90
15.6 = Redline MT-90 75-90
15.0 = Elf Tranself Synthese FE 75-90
16.7 = Motul MOTYLGEAR 75-90
6.3 = OEM G52 (part numbers G052726A2 / G05272601)
OEM G52 did not shear down at all in 43,000 miles of use:
V@100c: New G52 = 6.3, G52 after 43,000 miles = 6.4
Additionally, in these crazy unseasonably warm temps the Motul Gear 300 shifts fine - but early yesterday morning when temps were in the mid 40s - the first few shifts with Motul Gear 300 were noticably more effortful than the G52 ever was - even at below 0 temps.
Point being that even though Motul Gear 300 has an outstandingly low pour point (flows to -60)...
**the 75-90 viscosity of common gear / manual transmission oils is IMO not suitable for use in VW transmissions where G52 is specified.**