I saw the report useing Amsoil and each filter change the oil thickened. I guess if its not that bad a thing or someone would explain why these two 0-30 oils do this. Every oil has something that may not be acceptable by this boards standards. All I know after looking at the useable oils by the different oil companys AMSOIL recommends 0-30 for all 4 of my vehicles.So I will add a oz.a qt.of LUBECONTROL to the mix and the plot won't thicken.
But Amsoil thickens at 4000 miles.
Please define "thickens"
If Amsoil (any variety) thickens out of grade at 4000 miles in your car, there is something wrong with your car. That's not an excuse, that's a fact. In the same car, same conditions, I'll bet Mobil 1 thickens as much if not more, percentagewise. And yes the M1 may still be in grade, but thickened more.......somehow people forget where the viscosity begins.
Any oil will thicken from oxidation and soot in suspension when ran long enough .
Those low cost dino's that shear just are not getting ran long enough . Eventually they would come back into grade .
Some labs don't flag the oil till it thickens by 3 full cSt's from new starting VI .
This is the third analysis of Amsoil S2K 0W30 in the vehicle with 42,972 miles total. 4,435 miles on oil.
Oil changed at sample.
Fuel, Water, Glycol - None
Visc100 13.95 ( Abnormal )
The last sample was also abnormal Visc100 @ 13.16 and was atributed to short trips and colder weather.
As of today, the changed oil(S2K 0W30) after the above sample has 2028 miles on it. Anyone want to send me a free oil analysis and I'll take a sample and send it off.
If not, I'll just change to M1 in a month.
For the lab to say "abnormal" is a bit strong for a 30 wt moving up to 13.1. Per SAE, one grade change is allowable - I am not saying your oil didn't thicken, but at 13 it just moved into SAE 40 territory (12.5 - 16.3). The additives look strong as does the TBN.