I've been using M1 0-40 in everything I own for many years (VWs and Volvos, including an '09 XC70 T6), but I just bought a '15.5 XC70 T6 with a CPO warranty. Since these things can and do have ring problems, I want to make absolutely sure that I use the "right" oil according to Volvo so they can't deny coverage in the event of an issue, but I can't really get a straight answer about what's right. I figure BITOG will have some opinions... -My manual and the website says the cars need 0w-30 A5/B5 -The dealer that sold be the car used Castrol 5w-30 and the local dealer said 5w-30 was specified in the manual (see above) -Volvo "recommends" Castol Edge Professional 0w-30. That's not readily available in the states as far as I can tell, though you can buy quarts at the dealer for $$$$ -Lubri-Moly Special Tec V 0w-30 is "Volvo approved" and is about $38/5L at Amazon and FCPEuro (not too far form me) -Pennzoil Platinum, Ultra Plat, Mobil 1, and Castrol all make a 5w-30 A5/B5 and are cheaply available down the street at Wal-Mart So? What would you do? The car has 38k miles and is under CPO warranty until 100k or 2025.