I own a Baleno 1.3 ddis Baleno and the user manual suggests 5w-30 A5B5 Oil. Recently i went through my service records and came across quite a few instances wherein I noticed the service centre filling in 5w-40 A3/B4 Oil of Mobil. I understand that switching over to 5w-40 isn't going to do much of a harm to my engine. But i would like to receive some good suggestions regarding oils for ddis engines. I have personally felt that there arent much threads in this forum discussing about oils and their specs. Would be in the good interest of all automobile enthusiasts to discuss about this since the ddis/multijet engines are used in lakhs of cars and has aptly earned the title of "National Engine". Also how about purchasing oils from e-commerce sites?