Took my VF2 Calais V6 to the stealership today for a regular service. Just noticed on the invoice that they have used a different engine oil spec - 10W30 instead of 5W30 (recommended by Holden). Should I be worried?
Within the
owners manual, car manufacturers used to have a oil spec chart that showed viscosity rating against temperature while stating oil must meet for example API-SG classification. Manufacturers seemed to move away from providing these charts starting some years ago...
Added to the loss of those viscosity charts, GM jumped on the oil spec licensing bandwagon and Dexos Oil was born..... but Dexos is not a viscosity rating just as API is not a viscosity rating....
For the VF, Holden specs Dexos 1 class oil at a 5W-30 viscosity rating... Though I doubt it would cause a huge issue, I’d expect a Holden dealer to follow the manufacturers recommendation and use what is specified. I’d only expect a change in specs if Holden has provided a technical advisory or such to alter oil specs.
So, being that the dealer should do the correct thing, I’d ask them to provide a copy of the Holden technical advisory that altered the oil spec or change the oil for the correct grade... The only issue is how much you trust them. They could easily say it was just a paper work error and it’s actually got the correct oil grade & viscosity in it... they may even say they will change the oil and keep you around while they ultimately do bupkis... So do you trust them?