I've found the extra lubricity of Astroglide gets me a few extra MPG. It does make the car smell a bit funny though.

 

Don't worry Rakeem,

Your fellow Trini has sent you a PM on the topic of oil.

Paul.

 

Because the engine is japanese?

 

just had first service done at dealership and they used 5w30

 

But we all still humans arent we ?

2 eyes, 1 nose, 2 ears, 2 arms, 2 legs, a body, walk on 2 legs, etc

5w30 baby

 

thanks to all...

 

I'm changing my oil this weekend and I'm going to use 5w30. I've got 1700 miles on it so far.

 

not this again, oh well.

20 is too light, they only do 20 for emission reasons. Do 30 weight at least.

 

No, people use synthetic oils.

Simply because... there is no good reason not to use them.

 

free post?

 

They are more expensive, and if you change your oil often enough, it should be fine. Of course, they are better with heat.

 

You need to change synthetics as often as dino. The additives are pretty much the same. Oil change intervals are based more on contamination and the additives getting used up rather than the oil itself wearing out.

Ken

 

Mazda says use a 5w20 non-synthetic in the US. There are doubts about their reasoning. It has been asked before whether heavier weights are acceptable, and I got an e-mail response from Mazda NA saying that in warm conditions they are. They won't comment on synthetics as they haven't tested them, but don't recommend them as they haven't tested them.

If you want to follow the Mazda's recommendation to the key, 5w20 non-synthetic meeting SL certification. If you want something heavier but don't care about synthetic, a heavier non-syn w/ SL certification. If you want the absolute best protection without regard for warranty hassles, then a synthetic meeting SL of at least 5w30 weight is what I'd pick. Mazda technically has to prove that the fault lies with the oil in order to alter or void your warranty due to it, but they may hassle you.

It's really up to you and searching. Either use something that Mazda officially approves of or search and come up with reasoning for your alternative choice. There is a ton of debate as to what is "best". The debate arises because there are theories that Mazda recommends the oil they do because of emissions/mpg or lack of testing rather than engine longevity.

I use 5w20 Royal Purple as my aftermarket warranty requires that I follow the guidelines in the owner's manual (5w20 and SL, doesn't mention syn!). It's the best I could find while still meeting those requirements.

 

As long as you premix with maple syrup, it's not that important.

 

That's good stuff. I don't think the renesis will appreciate the taste though, whoever disassembles the motor may though!

 

I think if you went to the Middle East and asked about religion or politics you'd find more agreement than when you ask about oil here.

Interesting mix of old and new beliefs on oil. If you're old enough to remember Tom McCahill, he always recommended using a grade heavier than what the manufacturers specified. He carried the belief that manufacturers didn't know what they were talking about with oil.

He also believed that oil companies promoted new things (like multi-grade and detergents) that were bad for your car. We see a bit of that here with folks who don't like the new SM oil, but mostly we see adherents to the oil companies promotion of synthetic oil.

I don't have enough real knowledge about oil to recommend what to use. Other than having a feeling that mnaufacturers (both car and oil) must know something about their products, and that one grade heavier isn't going to hurt anything.

Ken

 

I think this is the one question that is NOT simply personal opinion that will never get answered on this forum.

 

Canola Or Peanut oil are your answer.

Please do not use Olive Oil.

 

I personally stick to the 5w20 recommendation in the manual. (5w20 has less polymers (Additives) then 10w30 btw) Oil is what your car needs, not polymers and additives.

The polymers are what allows the oil to be multi viscosity. ie its 5 weight while cold, and becomes 20 weight when hot.

the lower the weight, the easier it flows.

Think of it this way, you have a straw and 2 glasses. One glass is full of water (aka 5w20). The other glass is full of molasses (aka 10w30). Your mouth is a high rpm rotary engine which needs some lubrication. Suck on the straw. Wonder which one was able to lubricate the fastest.

Or another way to look at it is that honey is a 40w5 oil. (or whatever). When its cold its very thick (40)... heat it up in the microwave and it becomes very thin (5).

While it's said a heavier weight oil may increase the longevity of engine parts vs wear and tear -- if the oil can't flow good enough in the application, it's not helping anything. But in actual fact, the lower weight oil will prevent wear during the all important cold start and warm-up period. (providing better lubrication and protection).

Heavier weight oils give the perception of longevity due to the properties of being able to mask problems with sealing and compression. (due to the thicker "skirt" of oil covering the parts).

As far as synthetic... i dunno.. i'd rather not have it consumed by my engine as an expensive snack.

 

It appears to me that it is perhaps worth moving to a heavier weight oil as the engine gets older, and tolerances get wider, thus helping to protect better when hot. BUt it also seems that a relatively new and tight motor would benefit most from the thin weight oil, much as is true in piston engines.
Also, I saw enough on staticlag's crusible tests to avoid synthetics.
I'm sticking with 5w20 for at least 50k, then may move to 5w30 and may continue to 5w40 after 100k if applicable.

 

I have been using 10w30 royal purple for a while, and using the sohn adapter ... full break down, details, and pics of my engine's internals after 51k miles, almost half of which with FI:

https://www.rx8club.com/rx-8-multimedia-photo-gallery-6/charles-hill-engine-rebuild-51k-turbocharged-rx-8-a-148395/

I'm sticking with synthetic... thicker oil doesn't matter for clearances since I'm not injecting it into the engine for seals. 5w30 dino for the first few hundred miles (mostly cause it's cheap), then I'll go back to royal purple. 10w40 or w50 range.

 

I have just switched from GTX 5W20 to 5W30, at first the engine felt a little bit tight, but now it feels much smoother than before after 500 miles of "burn in ?!"