Yet another rotary-newbie oil question
 

I believe Mazda puts 5W-20 mineral (dino) oil in the new cars. Where I live (tropical weather) one cannot get oil lower than 15W-40.

1. Is it OK to mix oil of different weight? I read in another thread that it is not recommended. But I really do not have much of a choice.

2. Can one use synthetic oil at the first oil change when the original oil is mineral oil?

uhh try searching...
yes
no
the answers are really more complicated than this, but in general, with engine oil, there is nothing wrong with mixing.
the engine burns oil, and synthetic is not recomended....

You bought a US spec RX 8? I believe that different areas of the world may have different specifications for engine oil to be used in the car.

The best place to look for this information is first in your owner's manual then if it tells you to use an oil which is not readily available, I would try e-mailing Mazda and the dealer from which you bought the car. Any advice that we give you will not protect your warranty, but advice from Mazda in writing will protect your warranty.

Sorry that I can't be more helpful.

I am sure you can get it shipped at a reasonable price from one of our sponsers. I wouldn't take a chance.

Thanks to alll for your help.
I got a JDM spec RX8 Type S.
The climate here is similar to Singapore's (ie hot and damp) and on the far-east forum I remember some people saying that they've been using Castrol GTX 20W-50. So maybe that for warmer climates the thicker oil is OK.
Any feedback from our Far-East owners would be great.

From what I've been told and read in the forums, the lighter oils will give slightly better fuel consumption, while the thicker oils are better for engine protection. I would rather have the latter.

You read Japaneese . . . 'cause if you don't I can definitely see why you are posting for the information.

There is a particular section of the forum at the bottom of the regional list for far East quests.

I pulled this thread from that forum,

https://www.rx8club.com/showthread.p...threadid=18441

but if doesn't have what you need definitely ask in that forum because they will happily help you.

All the best - Haze

I live in Houston and had to go to two auto part stores before I could find 5W-20 that wasn't synthetic. Not a huge deal but it's not the world's best-selling oil. While I was standing in the first store, eyes roaming the shelves, my dealer's statement about "we're still trying to locate some 5W-20 oil in the Houston area" rang in the back of my head. I was beginning to think that he might have been telling the truth (God forbid!) But anyway, while they weren't over-stocked at the second store (they had two quarts total that I could find), at least they had a spot on the shelf for it. I'm assuming if I'd picked a different "first store" that I just as easily could have found 5W-20 aplenty. Time will tell.

I assume I could find the answer to the following in an archived thread somewhere but it's easier to ask the forum. When the oil level is showing up slightly above the bottom hash-mark on the stick, what volume is required to bring the oil level back up toward the top hash-mark on the stick? In other words, when I'm running near the bottom of the "okay range", how much oil should I add?

Ok, from what I have been reading, I conclude that:
1. There is no problem mixing oils of different weight.
2. I guess if some owners have switched to synth oil, it is ok to mix synth and dino oil, since one can only drain out half the original oil.