Originally Posted by shind3

xW-20 oil is only specified to gain those last few tenths of a percent to help comply with EPA fuel mileage regulations.

And since there is a huge percent of the population that thinks the 'W' stands for 'winter', I'm going to reiterate the following.
The 1st number succeeded by a W is nothing more why arethan a representation of the Kinematic Viscosity of the oil at 40 degrees Celsius usually in units of centiStokes (cSt)
The 2nd number is nothing more than a representation of the Kinematic Viscosity of the oil at 100 degrees Celsius usually in units of centiStokes (cSt)

There is a 3rd value that is most important for those that track their cars. That is the High Temperature High Shear (HTHS) test which is performed at 150 degrees Celsius.

10W-60 is perfectly fine to use in a track car that doesn't see too many cold engine starts. It is frequently used in Japanese S2000s. If I had a bigger R&D budget, I would run this oil on the street and do an UOA on it. My hypothesis is that it'll be just fine. Fuel mileage will suffer slightly but that's it.

For all you guys that drank the kool-aid on how the S2000 engine is so 'modern' and 'tight', here are the main and rod bearing clearance limits.
Mains : 0.0007 to 0.0016" (service limit : 0.0020")
Rods : 0.0012 to 0.0021" (service limit : 0.0024")

Let's compare it to an engine designed 10 years prior. Nissan's SR20.
Mains : 0.0008 to 0.0019"
Rods : 0.0007 to 0.0018"

So please stop propagating the notion that the S2000 engine is some sort of special unicorn. The only reason it made big news at launch was because Honda installed a big ass oil pump that provides enough flow to maintain adequate oil pressure at 9000RPM and the camshafts to complement.

Originally Posted by shind3

LOL, this is exactly opposite of the truth.
Official S65 Bearing Specification/Clearance Wiki

Originally Posted by shind3

I guess posting facts that are opposite of the blatant misinformation spread throughout the internet is construed as being 'angry'. You clearly are not part of my target audience. My target audience is not afraid to reassess their stance based on facts regardless of what their past beliefs may want them to.

And for anyone reading that cares about what I think, I run 0W-40 oil in ALL my cars (both NA and FI variants). Though I tend to subject each one to extended periods of abuse from time to time. If I didn't, I would run 0W-30 in ALL of them.

I would also encourage the reader to gauge subject matter credibility of the poster before accepting their opinion in equal company.

Also, EricLavato, you fabricated a typo into my quoted message in the 3rd line. I suspect you began to type your message before realizing you were posting in the middle of my quote. At which point you moved the cursor but left your defecation in the middle of my quote. Thanks, buddy. You speak volumes about yourself.

Originally Posted by shind3

xW-20 oil is only specified to gain those last few tenths of a percent to help comply with EPA fuel mileage regulations.

Originally Posted by s2000Junky

I stand corrected on the bearing clearances. I forgot about the "recommendation" to change these bearings as a preventative service at 60-80k miles, which is a big reason why my buddy sold his at 60k. That's unfortunate. Might have been prudent to run a thinner oil in this engine then a 60w! Makes little sense to me why BMW clearly dropped the ball on spec.

Originally Posted by SpitfireS

Nah. Thinner oils tend to get better and better in holding up the needed film strenght to keep parts apart.
The other benefit is less pump loss. Why pump thick stuff around when you don't need to?
The more important benefit is you pump more oil around at higher rpm as the pump bypass opens at higher rpm with a lower viscosity oil.


May I suggest you try to find the SAE J300 spec on the world wide interweb?
Read about it, please.
It's too late to say: "Read it BEFORE you post about oil", but yeah...


You'll find your precious 10W60 will quickly shear down into a 40 weight or so.


I thought it was because it produced 120hp/L @ 9000rpm while being N/A and was Engine of the year for 2 or 3 years in a row?
No?

Originally Posted by zeroptzero

5w40 is a good idea for a boosted street setup, I run Red Line 5w40 on my NA ap1 as a personal choice. 5w40 will work well at the track as well. If you start tracking the car you really need to monitor your oil temps, viscosity choice is best done based on oil temps as oil becomes thinner as temps increase. I don't see any situation that would need a 60 weight but everyone should run what they like, oil is a very personal choice and there are too many opinions out there that have very little facts behind them. Nothing sparks a good argument better than oil recommendations.

Originally Posted by Chuck S

Order a free engine oil analysis kit from Blackstone Labs and pull a sample. The kit is free but you pay for the test. Results will be highly informative if you do it every oil change.

I can't easily find any CS data for engine temperatures over 100°C and at that temperature 60 grade oil has 2.4x thicker viscosity than 30 grade. Lubrication needs oil flow. I've seen 10W-60 recommended for air cooled motorcycles.

-- Chuck