I have seen posts where RX-8 owners use syn. oil however my owners manual says not to. Reason please. Thanks.

Dr. 8

 

search. It's been discussed, killed, revived, slaughtered back to death. And now you've pissed on it. Good job

 

word

 

Doesn't anyone ever use google anymore??? LOL...

 

synthetic oil is the devils juice

 

I'd rather use real oil.

Ken

 

Synthetic is fine in the Rx8. I recommend a 10w-40 weight minimum for my motors.

Mazda did not like how one synthetic left a few deposits years ago so they do not recommend it for the general public as opposed to saying you cannot use brand X. However, it is recommended in all their race motors.

Now that I have that out of the way. If you use synthetic you run a chance of voiding your warranty w/ Mazda.

I put my own money behind every engine build and I recommend it to all my customers. There is a huge thread that is 60 some odd pages long on it.

Good luck and welcome aboard.

 

Use regular oil or recommended, it works wonders. You don't really need synthetic for this kind of engine.

 

Like others said, if you use synthetic oil you risk voiding your engine warranty with Mazda. That could be costly and not worth the very little difference in just using the dino oil.
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1973-2011 Seven stock and modified Rotary cars owned and driven over one million miles on street and track.

current RX: a 2008 40th Anniversary Edition RX8 w/ Mazdaspeed Cold Air Intake

 

Just stick with regular oil. Its cheaper and your gonna burn some anyway which might get a little more costly if you use synthetic oil.

Search next time please.