Here’s the problem. The owners manual for my 09 Mazda 3i touring (4spd auto) says that I’m supposed to use Mazda M-V transmission fluid. This is NOT the same as Mercon V according to some people but it is the same as ford FNR5 which is compatible with Mercon V. My dealer says Mercon V is fine, some other dealers don’t. What I’d really like to put in is Mobil 1 synthetic. Mobil 1 synthetic says it’s compatible with Mercon V but doesn’t say anything about Ford FNR5 or Mazda M-V. Any ATF specialists here can help me untangle this.
Don’t mess with transmission fluid…If it doesn’t say it’s compatible with you vehicle then DON’T use it.
BTW…most of these special ATF’s ARE synthetic fluids anyways…so don’t switch to Mobil 1 because it’s a synthetic…
What should I do then since my local dealer, the only one in my town, is the one who told me that they use Mercon V not Mazda M-V?
Here is a Mazda TSB about it. I have no idea whether this one has been superseded by a later one, but perhaps you should ask your local dealer if they are familiar with this TSB. Its main purpose is to tell you not to use Mercon V where M-V is called for.
The dealer didn’t design or build that car. Trust what the manual says.