Best oil for the Renesis?
 

I plan to buy some 5W-20 oil for my 8 soon. What brand do you use and for how long?

1.3L

5w-20 penz
 

Been using penzoil, good luck so far- I change oil/filter every 3k. I plan to keep vehicle a long time.

I used Penzoil at first but switch to Castrol (just because I use it in everything else I have) and found that the Castrol leaves a little less soot funk on the pipes.

You'll probably get a lot of opinions, but my 2 cents is for Castrol, also.

i agree, you will get many responses. i have almost 800 miles on mine and changed my oil at 586 miles with castrol gtx.(5w-20) i bought a mazda filter for the first change, but plan on using a k&n filter. i also will be changing my oil and filter every 3k miles.

yamajj

I use Mobil1 10w30 because it's widely available, tolerates extra heat, flows well, and I've been inside engines that ran Mobil1 and was amazed at the cleanliness. No I'm not worried about it being synthetic or the "wrong" weight.

I've been using Castrol Syntec, which from my understanding is simply extra purified dino oil with added synthetic detergents. Have been considering switching to Royal Purple.

Castrol 5w-30 and PureOne oil filter. The 5w-30 hasn't affected gas mileage either.

Navydood....
 

If you research the specs, the Castrol 0w30 is a MUCH better oil, in every way.

(and no, it's not too thin, at 12.2 centistokes,it is actually THICKER than the 10w30!)

Link to analysis...

S

I was talking to my service guy just this morning while getting a free oil change at the Mazda dealer here. First off, he was bragging that MazdaUSA rates them as the #8 service department in the country. That would lead me to believe that they know what they are talking about. Secondly, they made it clear that they would ONLY use Valvoline 5w-20 for the RX-8.

I make no claims on this, just thought I'd pass the info from them onto you.

If you drive your car hard i suggest a synthetic, Mobil 1 is a good dino oil if you’re willing to run 5w-30, I however air on the side of caution and go with Castrol Part-Synthetic 5w-20.

I change my oil and filter ever 2500 miles, Advantages of part-syntx is that if your still going to have your dealer do the 5000 mile services then its harder to notice (visually yeah yeah yeah) that it's synthetic oil especially because it mixes with 3quarts of whatever you had in the engine before because you can't drain the oil coolers.

Now as for the Rumors about synthetics not being good for Rotaries yada yada. In my opinion there are 2 ways to look at it. Some say that you shouldn't use syntx because the oil seals in the rotor require a certain amount of friction to seal properly, and syntx coefficient of friction is too low, they believe the best type of oil to use is mineral.

The reason i say that if you drive your car hard, especially for extended periods of time (ex. track, i would never take my car to the track without syntx), is use Synthetic because it burns at a higher temperature but the flash points are the same as Natural oils.

Far as the best oil i would say is Idemitsu http://www.idemitsu-usa.com/
They make Rotary engine specific oil, and once they come out with a 5w-20 for the 8 I don't think they'll be much contest to whose the best for our car. They also supply Mazda with OEM oil, so im going to hazard a guess and say that the oil at least from the factory that’s put in our cars is a synthetic, but that’s just a guess.

warning: smartass remark following:

you've been inside engines that ran mobil1? just how tall are you? :D

it's just a joke, i now return you to your oil debate.

yamajj

Valvoline here, I used Pennzoil at first, and the difference in color between the two is amazing - Valvoline looks much lighter, while Pennzoil is almost a coffee color even when new. My dad (a mechanic) told me that Pennzoil got into a lot of trouble for using recycled oil and selling it as new. After seeing the two next to each other, I think they're still using recycled oil.

-arattle

Using 5W-30 Quaker State here, and also change my oil every 2,500 miles.

I refuse to use pensoil on any of my cars. It tends to "sludge" very easily. This IDEMITSU looks interesting...

does idemitsu produce the mazda brand oil that you can get from the dealers?

Not sure, I'll ask Mike, CEO america, next time i see him.

i'm topping up with castrol syntec blend, 5w-20. i've heard the pros and cons of using synthetics so it seems like a good compromise. it meets the API SL / ILSAC requirement noted in the manual. the price is right, too.

I doing in the exact same thing for the same reasons.

Great minds think alike. :D

The Idemitsu (sp?) sounds interesting. Anyone on here using it?

I am a die hard believer in Royal Purple.. I use 5w20 in my 8 and have not had any problems.. and no more soot out of the exhaust either! I plan on changing the filter every 2500 and the oil every 7500

Though, I don't recommend using a synthetic until you have 2500+ miles on the car.. that way the seals can properly set.. or so I was told by several rotary mechanics..

Castrol 0w30...change oil every 3,000 miles.

I would be interested in the evidence behind this. I recently read of an oil study by an independent testing lab that showed Pennzoil had a much better additive package than any of the competitors including Castrol. I think that the important thing is to change the oil and filter regularly with a quality brand. My RX7 went to 140000 without any engine problems and was still going strong when I sold it. I used all types of oil but it was changed regularly.

As for filters the ones that come with the car the best and they are made by nippon denso (sp.), if you use mobil one filters consider this: If you go buy a generic walmart brand filter and look at the part # on the bottom lip and go buy a mobil 1 filter and look at the part # there the same :eek:

Didn't I ask this exact question a couple weeks ago and get excoriated with "use the search, stupid" and "close this thread"? You guys are so unpredictable. :p