I am asking for any experience regarding the transmission fluid for this vehicle, 2012 BMW 335is automatic trans. It is at 50,000 miles and 5 years old, and I wish to change the ATF, but the dealer nearly refused to do it, fine. I called two other dealers and the service mgrs were in agreement that it is a lifetime fluid, leave it alone or trouble will occur. The items they have recommended and I have performed are flush coolant, differential fluid, and follow the oil change meter. Of course I do not and change every 5000-7000. So, the question I have; does anyone have a good reason for never changing BMW ATF? I have modified this vehicle and feel it is important to change the ATF. In the other vehicles, I change the ATF every 25000-35000 miles, and have not had a failure for several cars with even 250,000-350,000 miles (maybe LubeGard Red helps a little). I would like to use MaxLife ATF on the BMW, as it meets the spec and add LubeGard Red. But the overpriced OEM Pentosin can be used if it must. Thank you for any experience you can share. BTW, I have been using Euro Castrol 0w-30, but it is becoming difficult to find. Do you think Mobil-1 0w-30 Advanced Fuel Economy is alright in this slightly modded N55 3.0L turbo engine?
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