I have 550i 2009 and 2010 with naturally aspirated 4.8L T62TU motor. I have always been using Mobile 1 0W-40 in these cars. Right now there is a crazy rebate on Pennzoil and I was considering trying 5W-30 Ultra oil. Both can be sourced at Walmart. It is not euro approved oil and the Walmart...
I have a few vehicles that I don't put many miles on. Mostly driven during the summer time. I have been typically changing oil after 4-5k miles or every 18 months. Now I drive them even less frequently and was wondering if I am wasting my time changing oil after 2k miles if they don't get driven...
