I sincerely apologise if this topic has been covered previously guys & I'm new to this Forum with this being my first Post !! I'm the owner of a 2010 Mazda 6 iTouring Plus / 2.5L with a newly purchased used 2010 Mazda 3 GT /2.5L after my kid just wrote off my 2001 Protégé ! I'm a Mazda Fan !! What can I say ? My 2010 M6 has been switched over to 0W20 Synthetic without issue... SOO the Question: The M3 vehicle has 91,000 KM's on it and the original only owner had the vehicle serviced throughout it's life at Gyro Mazda in Toronto since new with 5W-20 Conventional oil !! Can I switch this M3 to 0W-20 Synthetic OR have I answered my own question ? Also, anyone using K&N HP-1002 Oil Filters ? Any feedback is greatly appreciated ! Glad to be on board !! Cheers !