Engine oil Castrol or Shell

Castrol Power 1 ultimate is great and cheaper too.

I would recommended shell ultra 15w50 . KV100 is 20 which is thick as fuck and won't shear down quickly. Mogul 7100 is thin and will shear down to 40 grade and internationally considered garbage oil. Shell is made of group 3+ base oil so its going to perform better.

Rotella 5w40 only. I daily and track mine

but real talk: Castrol GTX Synthetic 10w40 in Tennessee summers and 5w40 in winter.

5W30 Castrol edge full synthetic

Castrol Syntec 5W-30, because of this: [https://my350z.com/forum/engine-and-drivetrain/258663-vq-oil-analysis-and-info.html](https://my350z.com/forum/engine-and-drivetrain/258663-vq-oil-analysis-and-info.html)

Between it and the Castrol Syntec 0W-30 it has less wear indicators in the oil than any other brand, at any other weight.

Redline and motul are the best but I’ve been running catrol for 50k+.

On an old e36, 5w30 full synthetic no matter the brand would often cause some leaks. Switched to some thicker Rotella oil made for diesels and suddenly no more leaks.

As far as the castrol goes I bought a used 2018 Kia soul that had a slight knock in the engine for ultra cheap and I was able to make that sound go completely away once I switched to Castrol edge. My vehicle also seamed to burn a lot less oil.

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.