Oil viscosity confusion

[edbostan]

I drive a 1.2 tsi engine which is doing me proud. At the first ever oil change the dealer put in 0W 30 viscosity Shell Ultra oil for changes. The next oil change the dealer had changed oil supplier and put in Castrol Edge long life 5W 30. I intend to change the oil myself so on the websites for the oil companies they have a Find the right oil search facility. I have found that most companies recommend 5W 30W for long drain intervals but 5W 40W for fixed servicing. Why is there need to put in a 30W for long life and 40W for shorter drain intervals?

[Ootohere]

The need for variable / flexible servicing with a TSI or TDI before Skoda changed the oil they fill at the factory around 2018 is to VW 504 00 / 507 00.  So that might be 5w 30 FS III.    Newer engines VW 508 00/ 509 00. So 0w 20 FS IV.       If you want 0w 30 FS III for a TSI then you can use that.  If you want VW502 00 so 5w 40 FS for fixed servicing use that.    For TDI,s it is long life oil required even for fixed service intervals.    With Long Life oil the clue is in the name.     Back with some Euro 5 TSI,s the oil might be Long Life but the engines were short lived or heavy oil drinkers.

Edited 7 May, 2021 by e-Roottoot

[edbostan]

 Interesting. I will refill with Shell Helix Ultra 0W 30W as the engine was quieter on start up