5W30 or 10W30?
 

a salesman told me that 10W30 is better for the engine than 5W30. the only reason mazda still recommends 5W30 is some political/business issue but all his service people use 10W30. anybody hear anything like this?

anybody have recommendations on brand? is it bad to top off my oil with a different brand than what's already in there? or is it ok as long as they're the same grade?

how often should i keep it topped off? i don't really mind topping it off every time i fill up on gas. but is it bad in any way to always try to keep the level near full? is there such a thing as too often?

Uhhh you mean 5w20 right?

Read pages 8-9 to 8-10 in the manual. There is no reason to do otherwise.

Depends on whether he's in the U.S. or not. 5W30 is the standard oil outside of the U.S.

There's been a bunch of speculation on the forum that the 5W20 was selected in the U.S. to meet EPA requirements and may not be the best choice, especially in some climates.

i use re amiyama oil for na rotor its 0w30

5W-30 will be better during cold starts, but 10w-30 will be better at operating temps because it has less viscosity index modifiers. But most wear and tear occurs during cold starts, so the 5w is what I have been using.

I have used 5W30 for the entire time I have had my 8 on the road. My dealer has performed all oil changes and always used 5W30 as well. I live in a colder climate area
(NH - USA) so for me that has made the most sense.

Hiya zeliggusgus. Glad to see you researching the RX-8; there are a few really definitive oil threads on this board already. Try this one:

https://www.rx8club.com/series-i-tech-garage-22/rotarygods-rotary-oil-tech-blog-69805/

Also, be cautious of what the salesmen tell you. ;) One RX-8 salesman told me my RX-8 didn't have a power steering fluid reservoir because the power steering and brake systems were combined. Obviously, he didn't know the steering was assisted by an electric motor instead of a hydraulic pump (and thanks to him, neither did I until Go48 posted shop page manuals for me on this board).

He he he!

Cold weather 5-20 Warm 5-30