oil changes for RX-7

[David88vert]

Never use synthetic in a rotary. Synthetic does not burn clean. You do not really want to inject synthetic into the combustion chamber.
MazdaTrix has the best explanation for it: http://www.mazdatrix.com/faq/synthetc.htm

I have spent a lot of time and money investigating oil and motors - and mainly on rotarys. I also am one of the few people that has not blown up numerous 13Bs. Now if you have the oil injection system blocked off, and are running pre-mix only, then synthetic is ok, but I still wouldn't waste the cash on it.

It definately does not hurt to change the oil very often, but your driving style and how hot you get the oil makes a difference. Most street driving is fine at 4K and under. Of course, if you are racing or doing track days, you should have fresh oil before you start, and change again after finishing a race/track day.

A good online knowledge base: Felix has had one of the best rotary sites for over a decade. He is also very knowledgeable about rotarys and oil.
http://mrmazda.no-ip.com/