Opel ASTRA 2017 Owner's Manual page 286

284 Technical data
below -25 °C
down to -20 °C
1) Permitted, but usage of oil with dexos quality is recommended.
All countries with international service interval 3 276
SAE 0W-30 or SAE 0W-40
SAE 10W-30 or SAE 10W-40
1) 1)