Since I am new here this subject may have been talked about before. In my owners manual, it says that Mazda has never done tests to verify is Synthetic oil is recommended in a Pro5!!! Actually my dealer even thinks it is a waste. I put it in everything I own from lawnmower to snowblower and have never had problems. I used to put it in my Hondas as well. What gives here with Mazda?

 

the condition of the oil is more important han the type of oil. Personally I'm using synthetic in my car, but only because I pound on them pretty hard. If you don't mind the added cost check out www.royalpurple.com they average about 3%hp ad torque increase over conventional oils. I've used them in my 8200rpm SHO and it works amazingly.

 

I bought my car new in Feb of this year and have 26K miles on it now. I use Amsoil and have not had a problem. I have been very pleased with it.
Jeremy

 

I use Mobil 1 in mine and have had no problems. Do you NEED synthetic? Probably not, but do you WANT synthetic? Why not?