But this thread is not about Castrol.
I am aware of this. It is a 0W40 oil though. If I had started a post about it (Castrol) I'm sure some might not have liked that.
I apologize for hijacking this thread.
Thank you for the link to the Castrol thread.
0W40 that OP asked about )Mobil1 Formula ESP) and 5W30 ESP are not same category as Castrol 0W40.
Castrol 0W40 is made for European gasoline engines, Mobil1 5W30 ESP is primarily developed for new diesel engines with DPF and SCR system, though in Europe is used also in gas engines due to low sulfur content in their gasoline. Mobil1 0W40 Formula ESP is also lower-SAPS oil (not quite like 5W30 ESP). So while Castrol is 0W40, that is THE only thing in common between Castrol 0W40 and Mobil1 0W40 Formula ESP.
Why more expensive? Castrol 0W40 that you mentioned is around $70 for 5 liters in Madrid, Spain. I was 10 days ago in Madrid in Wal Mart style store (Carefour) and they have bunch of oils, and Castrol 0W40, Made in Belgium is 55 euros for 5ltr. Some Low-SAPS oils are close to 20 euros just for one liter. They do have sale of some oils, but regular price is high. Take into consideration that is tax included and VAT in Spain on oil products is 21%.