Sticker under the hood says 5W-30 as you can see in the attached photo but dealer says they only carry 0W-20. Which oil is best? I have heard 0W-20 is lighter and will therefore flow better but will it provide adequate wear protection for the engine itself and turbos?

 

I would use what your car is spec'd to run. The fact that the dealer told you they only carry 0W20 is rubbish. That is what the SPA cars run. I find it hard to believe their service department only carries one viscosity. Ahem, I digress. Back on topic, use 5W30.

 

+1. Check your owners manual. Volvo gives temp ranges and advise on oil weight for severe conditions (including towing) . They also refer to Castrol which simply is a recommendation - The manual lists the standards required. You will find most premium oil brands meet all factory specs.

Volvo also posts the manuals online (free no spam site):

https://www.volvocars.com/us/own/own...owners-manuals

 

If it's a Drive-E, the spec has been updated to follow the extreme conditions in your owner's manual.