I have always used what is on sale, as long as it is full synthetic.
I do not use EURO oil in my VW, I use M1 or Castrol, no problems. My
TDI had 243,000 miles on it when it was bought back, and I used that
Rotella T6, then DELO 400, and that's $20.00 a gallon. I have around
140,000 on my '12 2.5 I5 Jetta. My '15 TSI had 175,312 when
totaled. So, I think I have proven that oil is oil, because I never use
what the Manufacturer says to use. Sure, they have different properties
and such, but I use whatever Synthetic I can get on sale.
AS far as properties? Check this out:
For some reason, I was getting high oil consumption with the Rotella
T6 (5W40) Diesel Motor oil. I switched to the even cheaper DELO 400,
and that problem went away. T6 would fill my catch can more than
two times every 10,000 mile change. The Delo, barely one... So,
I amusing M1 5W40 in my VW 2.5 I5, and was getting some consumption.
I mix in 2 quarts of that Delo400 5W40, and almost what I put in, comes
out every change. I don't know what it is about that Delo400, at $19.97
gallon, but it works... This 2.5 engine takes over 6 quarts of oil, so
2 DELO 400and 4.2 M1... I change my oil every 6 weeks, at 1800+
miles a week...