I just got the subject car from my in-laws. Doing some quick searches it seems there have been issues with that model eating piston rings. Volvo updated the oil requirements to full synthetic as well. I've always been partial to Mobil 1 and Pennzoil so I went to the Mobil website where they have a "find the right oil for your car." I filled in the info and here's what I got, "Based on what you've told us, your vehicle manufacturer recommends a 0W-30 viscosity and synthetic oil and oil that meets ACEA A5/B5. We currently do not offer any motor oils in the United States that meet these specifications." Does anyone here have any thoughts on this? Seems crazy that Mobil 1 doesn't offer an oil that works in the T5 engine. If that's the case I guess it's either Pennzoil ultra or Castrol edge, which is what Volvo pushes (guessing due to marketing).