I think the type of oil is more crucial than the change interval. I don't think we would have seen as many cases, at least with the 2012 5 cylinder, if Volvo had used and specified a full synthetic from the start. Case in point, my engine started burning oil pretty bad by 40,000 miles. Volvo's change interval for this MY was 7500 miles. Still being a bit old school I was changing the oil myself in-between, so every 3750 using the proper Volvo speced oil at the time. The scoring was bad they actually replaced the engine thankfully all under warranty. But I'm really glad this has worked for you.