Engine oil Mobil or Castrol

Mobil 1 10w30 with a bosch filter up here in Canada. Haven't had a tick since I started using it, at 110k km my engine is in good shape to begin with though.

the Mobil 1 is the 0w40 Euro Formula, and has the VW502.00 approval that being said, Mobil 1 5w40 Turbo Diesel Truck is also a good choice, but no VW approval.

I'm using Mobil 0w40 (502 spec) in my B5 Passat for 140K and plan to use the same oil for my GLI when the free maintenance ends.

In my gen 3, I've used Castrol OE Professional 5w40 (the Castrol in the gold bottle that the dealer sells - oil has a green tint to it), both when I did the 5k mile change and when the dealer did the 10k change.

Used Castrol 0W-30 in the past with the GTI and GLI. Pretty decent oil analysis numbers when tested.

I prefer Castrol 20w50 in my 1976 CB550, at least in the summer. Non-Synthetic

I'm using Castrol Syntec Euro formula which is a 0-30 oil. I've been doing oil analysis with every oil change since I got the car. This change was a short interval with just 1400 miles on the oil between changes. Right in the middle was a track day where I did about 130 miles on track, six 20 minute sessions. I think I was seeing peak oil temps in the 240s with very quick recovery back down below 220 during cooldown.

I run Mobil 1 5w30 and still change it every 5k. I could probably bump it up to 7500 or 10k but don't because I do it myself, and it isn't a huge cost or inconvenience to do it early.

I run the extended performance Mobil 1 in my Toyotas at 15k mile intervals, with an oil filter change every 5k miles.

10w-40 Mobil 1 is the best oil you can have for your VR6 engine. Besides superior protection it also takes longer for the oil viscosity to break down.