QUOTE(zeng @ Oct 4 2019, 02:48 PM)
To be honest, I was taken aback too when first came across this voa results.
From my readings around, VOA testings in Germany/Russia is more sophisticated then that in NA like Blackstone etc.
I don't doubt the 'ball park' figures in this test, though Labs do make mistake occassionally and there is always a margin of error in any lab testing, hence the requirements of periodic calibration of lab equipments.
I'd used HX7 10W40 before but not its 5W30 siblings, and I must concede this Helix HX7 5W30 SN is a quality engine oil in relative terms to other 5W30's .
noack of 6 is very damn good for a semi synthetic product, the baseline for SN if not mistaken is about 12-13%, so this is insanely good with a 100% margin from baseline!. Even many top tier fully synthetic can't reach that low of noack value at that viscosity range, only a handful that i know of, namely mobil1 esp (5.6%) and ravenol dxg (6%). Others like the venerable amsoil signature synthetic is 7.8% for 5w30. Even these top tier fully synthetic are around of 7-8%, some surprisingly at the higher end of 9%.
QUOTE(speedy3210 @ Oct 4 2019, 04:08 PM)
Shell's GTL basestock is well known to hv very low NOACK figure, not surprising in this respect at all. just that i didn't expect they use GTL base in a lower tier SS oil.
On the other hand, pennzoil platinum ultra and helix ultra ect c2/c3 (also using shell's GTL), is 9%+ noack, why leh?