I just took advantage of the sale at AutoZone, picking up some 5W40 European. After a little research, I am very impressed that the HT/HS rating of this oil is 4.50. That is compared to M1 0W40 being at 3.60.
I am eager to give it a try in the boy's new Rabbit!
By the way, while I am responding, would anyone suggest the Castrol 0W30 European for the 2.5L VW engine in the cold [censored] of winter?
One last question....If I run Castrol for 5k miles and want to send a sample to Blackstone, without draining the oil, how is the best way to do that? I was thinking of doing a test at 5k miles, then 7.5k miles and then...if it makes 10k miles (as recommended by my manual)....do UOA at 10k when I drain and change.