Ok, so I know there have been a million oil related threads on the forums but I came across an interesting statement in a pinned S2 Oil Filter discussion that confused me. I understand the oil pressure and flow rates are different between S1 and S2 engines leading to them each having slightly different OEM filters. In the discussion, one member mention that there are 2 OEM filters, one for the S1 and one for the S2, but he also mentioned a third one for the 09-11 R3 trims because of a higher oil pressure due to the dry sump. I am looking to see if this was actually true or not as the thread was locked soon after this comment. I currently use 10w30 Idemitsu Racing Rotary Oil in a K&N Gold HP-1008 Filter and have had no problems yet, but would definitely like to make sure I'm doing the right thing for my car.

Also if anyone has advice on the best vendor for Idemitsu Oil, I will take recommendations cause it seems most rotary vendors sell it around $10-12 per quart with $20-30 shipping.

 

I run the K&N HP-1008 in my 2004. But if you look on K&N's own site and look up your 2011, they indicate to use the HP-1010 for 2009 forward.

K&N Site

So while others may chime in about the OEM filter question you have, hopefully this helps on what you should be running on your 2011.

 

There is no dry sump on any factory rotary engines I am aware of. For most dry sump systems, like the one in my C7 Z51(RIP), the dipstick would be away from the engine block in a separate reservoir that holds the majority of the oil as the sump holds very little oil, hence the dry sump name.

AFAIK there is just one oil filter for all S2 RX-8. I just bought the stock ones because they are good and the local dealers sell them for CAN$10 a pop. Much cheaper than some of the fancy aftermarket stuff for likely the same quality.

As for Idemitsu, I don't think there is much you can do. If you are asking for something like Mobil1 (which has a special oil for Vette and Camaro that goes for CAN$25 a quart from the dealer), then I'd suggest either Rock Auto or asking a local Mobil1 distributor as both gave me much better prices. In my case RA won out. RA doesn't carry any Idemitsu stuff and I don't think Idemitsu has many big distributors around North America so yeah, rotary-specific vendors are probably your only choices. The vendors likely imported all the stuff directly from Japan so there must quite some customs, duties and shipping added on, unlike Mobil1 where a lot of that CAN$25 price is obviously bloat. US$10 wouldn't surprise me too much for Idemitsu.

 

When I first got the 8 the prior owner ran Idemitsu so I was planning to do so. Then after a bunch of reading on this site I decided to run Royal Purple 5W30. I'm not trying to turn this into a "which oil" thread, there's tons of reading you can do on oil here, lots of people run cheaper oil, but I can get RP at Autozone and a few other places in the big jugs and the expense isn't all that bad.

Jinx, just to be clear, where you say there is one filter for all S2's I take it you do agree that there is a different filter for them as compared to earlier years? Seems like the main point here is that Ian is running the wrong oil filter and should change over.

 

0000Yeah pretty much, Idemitsu is just too exclusive to get cheaply in North America. I personally just ran cheap conventional oil for CAN$20 per 5 litres on sale in my S2 and changed every 3k miles.

And yes, S2 oil filter is different from S1, per this post from ASH8. I suppose my "one filter" statement is confusing. What I meant was that all S2, regardless of trim, has the same lubrication system so the oil filter specifications are the same. If you run an aftermarket unit, make sure it has the same bypass pressure rating as the OEM one. K&N HP-1008 filter's bypass rating is rated for S1 spec, not S2 spec. Not the end of the world for street driving, but something to pay attention to.

https://www.rx8club.com/series-ii-te...-ii-r3-188392/

My main point was just that the OEM filter is just so cheap from a dealer and it's of decent quality, so why pay more for the aftermarket stuff?

 

This from the link Jinx copied above
S2 Oil Filter By Pass rating is 20.3—26.1 PSI
S1 Oil Filter By Pass rating is 11.4—17.1 PSI

If you buy other than OEM oil filter, make sure the bypass rating is 20-26 PSI or it will just be useless.

 

Thanks for all the advice guys! I will always take advice on oil seeing as Idemitsu is hard to find but I'm still a bit skeptical with some other brands.

As for the filter, I will definitely be using the S2 OEM now seeing that even the HP-1010 K&N Filter has the wrong By-Pass rating.