Hello I'm wondering if someone can help me. I recently bought a 2012 Mazda 3 with 98k miles. I'm going to change the transmission fluid but I'm wondering if it's necessary to change the transmission filter as well or is it enough to just drain it from the transmission drain bolt. Also does it matter if I use OEM transmission fluid or is it safe to use aftermarket transmission fluid that is compatible? Also one last question how often should I change the transmission fluid from here on? Thank you!
Change the filter and use any compatible trans fluid. Change it according the specifications in the maintenance section of your owner's manual. You can find it online if you don't have the paper copy.
if it has a serviceable filter, then yes, always change it with the fluid. It doesn't cost much.
