The 2015 Mazda 3 gs came with sky active technology. I read that Mazda claimed it is life time transmission fluid required no change, so I called 4 service centres from different dealer for advise. The answers are 50k or 3 years, 80 km or 4.5 years, 100km or 5 years, 200k or 10 years. One thing in common is that they don't suggest transmission flush but only drain and refill since it is a sealed unit. Any suggest on when should we actually do this. Thx