[michael95350]

I've ran Mobil-1 in every new car I've ever owned. NEVER any issues with it. In this instance, I am using Mobil-1 0W20 Advanced Fuel Economy "Asian" Formula (the bottle is marked "Recommended for most Hondas and Toyotas"). It is approved for GF-5 applications.

 

[michael95350]

I've had dealer (free) oil changes since new. I asked the mechanic what they use. 5-20 synthetic blend. 40,000 + miles and counting.......

That backs up some of the arguments in here that the service department is using the bulk oil versus what the manual recommends. The semi-synthetic is their bulk stock. May not be much of an issue between semi-synth and full on synth, but then again what's the difference between a Chevrolet and a Cadillac?

 

[michael95350]

Does anyone know who manufactures the Mazda moly oil? I'm guessing Mazda Corp isn't in the refining business. Can the same moly oil be bought under a different brand name than Mazda?

Mazda recommends Castrol in their owner's manual. This is just an guess, but I would suspect that they might use Castrol Edge 0W20 as the base then add their moly additives to it.