Engine oil Castrol or OEM Audi

Castrol EDGE Euro is also VW 508 spec.

The mechanic is absolutely wrong. You must use a 5W-40 C3 oil with the Fiat 9.55535-S2 specification, I use the Castrol Magnatec 5W-40 C3, which is cheap and easy to find, but any other brand with the correct specification is fine. A 0W-20 oil has insufficient pressure and film strength, and will lead to damage over time.

I have a 450k km 1.9 tdi, and a 300k km 1.6 tdi, i always use 5w30 castrol, no issue.

I would only suggest using \"premium\" oil brands, like Castrol or Elf, in correct specification.

Castrol Power1 is really good though

I change the oil myself...to ensure it's done correctly and with quality oil (I use Castrol Edge). And I go by the oil minder. I do smell gas during oil changes but it's not strong and never in the cabin between oil changes as some have reported.

I have a 2010 civic si, I use shell rotella T-6 5w-40 due to burning issues and one quart of Castrol 5w-30 high mileage full synthetic (I’m picky lol- but my car runs smooth and has consistent oil levels on the dipstick through the weeks after oil change)

Buy Castrol Edge engine oil for your Mazda 2.5, but do get the Mazda transmission oil.

Castrol is fine

Had a Q5 and it was a money pit. Oil Consumption got so bad I was putting in a quart every 400 miles.