Engine oil Castrol or Shell

My 10k UOAs on Castrol 5w40 were just fine, but VW 504 is mid-saps so it might not have as much staying power even thought it's "better" oil.

Our Tig is coming up on it's 4th change (every 5K) and hasn't lost any significant amount between changes. So far all changes have been the 508 spec Castrol 0w20.

I really like Castrol oil. I used the VW High Performance twice, and it was fine, but I still preferred Castrol.

Anything is better than nothing. I've tried most big oil brands but overall I like the Shell Rotella stuff most.

The approach to go with 10W40 is absolutely right - from my experience the best oil for that kind of engines! Take an expensive Castrol Magnatec Oil and it runs well.

I use the T6 as well and like it a lot. Other people in this forum have recommended in the past as it’s additives are supposed to be good the 4.0’s. Always worked well for me, it’s reputable, not the most expensive and if the additives do actually help, thats only ever a good thing.

Can't go wrong with [Shell Rotella T6](https://rotella.shell.com/en_us/products/full-synthetic-and-blend-oil/t6-full-synthetic.html). Full synthetic, JASO-MA certified and cheap.

Shell Rottela 5W-40 full syn.

new filter and oil (Rotella T6 highly recommended)

Shell Rotella T6 will change your life on n54