OEM is 5w30, I bumped it up to 10w30 and it's been great.

I think 10w40 is to thick, but thats just me even for an OEM stock clearanced turbo car.

 

OEM for S2000s is 10W-30. I use AMSOIL 10W-40. I've thought about trying Redline or Motul but that stuff is more expensive.

 

Hmm, I could have sworn it was 5w30 all this time...I must be thinking of my buddies vette or my friends mitsu.

 

Wow, sooo many opnions

First I would look for an oil with ZDDP which is a friction modifier that is not easily found in the US due to crappy legislation.

Second, if you are running higher temps then you will want to go from 30w to 40w to maintain the propoer viscosity when heated.

Personally I prefere Mobile 0w-40 or Carstrol 0w-30 b/c they have ZDDP, and work great in a climate like ours with subzero and 100F days.

Here this should explain things a bit better.
https://www.s2ki.com/forums/index.php?showt...&#entry15015689

 

i personally think many different oils can be used...

i have used Castrol GTX with ZERO oiling issues... if i were to use synthetic i would use Castol Syntec for sure or Amsoil....

prime example is Rob!'s car, he used the bulk oil that was used at his Lexus dealership, and his car had ~127k miles on it and made 772whp out of a bone stock (3mm HG) motor, his car proves a point to me.....

 

Most of the oil out there should never have any problems if applied in the correct way. What I do not like is the marketing that is done by many of there "Race Proven" manufacturers. What they should really be telling us is what is the oil PAO, Refined Base, what the additives are, more details on the viscosity......... That way we as consumers can make the best choices, unfortunately too many people believe that this is solely the consumers responsibility. This is why I try and post all the information I can on topics such as this one.

 

^ i do appreciate your informative posts, and as stated, for 90% of us, any oil from the local auto parts store will do just fine, i change my oil about every 1500 miles, so thats why i choose to run GTX versus running a expensive syn oil... If you change your oil frequently, any oil will get the job done...

 

where does everyone buy Amsoil @

 

Castrol edge 5w40

 

I'm running Mobil 1 0W40 Euro blend.

Usually run redline 10W40 but my supplier is out. boooooo!