Opel Corsa C with Z14XE engine, 598,000 km and continues without problems, without smoke. It consumes oil at 1 liter every 10,000 km, and this is when I drive it at high RPMs. It burns oil from the valve stem seals, and the head gasket has not been changed yet. Gas was installed at 500,000 km. I forgot to mention that the air and oil filters I use are Mann.

I put them in an Opel Corsa C 1.3 CDTI 2004 with 217,000 km and the difference compared to before is chaotic. Until recently, the "mechanic" at my workshop was using Repsol 10w40 and the car was still making the same noises even after a fresh oil change. By installing Castrol myself with a filter change, the noises at idle were greatly reduced and the car runs smoother. It will be seen over time if it consumes oil from them (hence the 4 stars), although I will probably prefer them again. Their price is great for their quality.

When the petrol engine is cold, it doesn't "rattle" as much compared to other semi-synthetic oils.
I think it is a very good product.
I will buy them again.