I've been suffering with the OEM Mazda manual transmission fluid in my 2014 6spd. The fluid is like $28 a quart or something absurd yet I manage to shear it out of spec within 15k miles of daily redlining and constant revmatch downshifts as I slow down. I have 60k on the car and have changed the transmission fluid probably 5-6 times now.
As soon as it starts getting crunchy thru my short shifter, a quick drain n fill instantly gets the gears sliding smooth as butter for another 15k miles...
I plan on trying different fluids during the next change. Already bought Redline MTF to see if it will be better then OEM. Otherwise, $60 transmission fluid changes until the wheels fall off.
Can't you find Mazda lube online much cheaper than $60 ?
Unfortunately, that's just the fact of life for this ridiculously expensive Mazda Lube. It's good stuff. Always makes my transmission smooth again but just doesn't last for me. Maybe someone with a Normal eco driving style can get the typical 60k miles out of it.
I'd be afraid of putting Honda Lube in the Mazda transmission of a new 2018 model.