Thoughts on Lifetime's Transmission Fluid—Actually, lifetime or a marketing trap?

> I own a BMW F30 320i 2016 model. The manufacturer (and the dealership) insists that the transmission fluid in my car is lifetime and never needs a flush. However, most independent specialists I talk to say that’s a recipe for a dead gearbox by 100k miles and recommend a drain/fill every 50k. For those of you with high-mileage daily drivers, have you stuck to the factory lifetime schedule, or are you doing preventative flushes? I’m torn between 'if it ain't broke, don't touch it' and wanting this car to last another decade. > > Click to expand...