Engine oil Castrol or RED LINE

i use castrol 5w-40 european vehicle. fully built and no issues at almost 30k

I am running Redline 0w-30 during the warmer months. It was the most reasonably priced group 5 ester base (with great reviews) that I could find. Oil temps during my last autoX event were down 15 degrees F, compared to a similar day with the factory recommended 0w-20.

My 07 Passat has 236k. I change oil every 5k, cam follower every 70-100k (20k is serious overkill), lots of coil pack changes (like 4 or 5), and that is about it.

I use the Castrol Edge oil. I was doing 7500 mile oil changes and on this last one bumped that up to 10k miles. I sent out the oil for analysis to decide if I want to step up to an even larger interval. The comments left by the tester: 'Your CX5's engine looks good in analysis! Your results look really good by comparison after the 10,000 miles. Metals are all within good wear ranges, with iron even showing below-average steel wear. Nice! Titanium is just an additive in Castrol. Very nice! Go 12k miles next fill.' I will heed their advice and go 12,000 miles on this next one.

Redline 5w-30 with an OEM filter. No issues and smoother start up.

Castrol German 0w/5w-40

Doesn’t sheer down…

I used Castrol edge cos that's what my audi used from the factory.

For my 1.6 diesel I use Castrol Magnatec 0W30 Stop-Start C2 which was recommended to me by cox motor parts (great store for Honda parts)

Castrol Power 1 isn't a bad oil, but I'd say not the best either. I have only used LiquiMoly as an alternative, so far and I rate is better than the Castrol but it did cost almost 2x as much too.

Castrol. I've just always used it. A bit of advice though, i'd recommend staying away from Pennzoil, I had to clean an engine out after using it. Nasty, waxy stuff.