Engine oil Mobil or Castrol

mobile 1 is a good brand. id go with it

Why not just buy the Mobil 1 and take it to the dealer?

My 2925 Passat is happy on the Mobil 1 esp synthetic.

I was running Mobil 1 for many years in my 14 ST3 and started with Mobil 1 in my now 16 ST3 but this year I swapped to Walmart brand full synthetic and haven't had a single issue except for extra cash in my wallet. It meets all the specs and I change it every 5 thousand miles regardless of how the car is driven. I'm at 86 k now on the odometer and she still pulls string like the day I picked her up.

I have never seen my 2017 Jetta low on the dip stick. I usually change it about every 5k miles using Mobil 1.

I've always run Castrol with no issues. The biggest thing is to make sure that whatever oil you use meets the spec required by your engine.

I use Castrol GTX full-synthetic 10W-40, as I live in Texas where the average temperature is hotter than the rest of the US and oil weather varies drastically. During the summer, I've considered bumping up to 15w-40 due to how hot my startup temps are on a "cold start".

I've personally run Mobile 1 full synthetic for 10k intervals ever since the factory oil changes ran out without issues.

Not saying it is better than anything else, but on my G60 turbo i used Mobile1 FS-X 5w-50 and will continue with this oil on my PG/ABA turbo.

Not certain what Castrol makes for a synthetic, but I know I experienced white foamy build up on my oil cap on a previous vehicle using Castrol. Switched oil and it stopped.