BRZ vs S2000 vs Cayman S (my take)

[ermax]

Originally Posted by bfrank1972

B) you shouldn't use any old weight you choose and ignore that design. Thicker oil has a harder time flowing through tight bearing journals etc. It really depends on tolerances in the motor.

Again, different oils for different uses. The CS-Cup is the same engine we have. They just specify the oil needed for the task at hand, racing. Not daily driving, not track days, not time attacks, not autox. I can guaranty they didn't specify 10W-60 with the goal of destroying the engine as fast as possible. If I recall the GT86 manual in Japan also lists optional oils depending on use. Same engine, same tolerances.

[Tokay444]

Originally Posted by bfrank1972

Here is a good/short article on the subject:

https://www.google.com/amp/s/blog.am...ty-of-oil/amp/

Basically supports both general ideas that:

A) modern motors are often designed for lower viscosity oils, indeed designed that way for EPA regulations

And

B) you shouldn't use any old weight you choose and ignore that design. Thicker oil has a harder time flowing through tight bearing journals etc. It really depends on tolerances in the motor.

Maybe the FA20 tolerances aren't that tight? Maybe they are but per Mike's contribution the fact that the oil cannot support flow/heat transfer as well as the lower viscosity oils is secondary to maintaining higher oil pressure during extended track runs - speculating here as I don't participate in any cup series, Mike may have a better idea about the real reason.

It is actually interesting stuff, thicker oils provide a thicker film capable of supporting greater loads (think oil supported journal bearings) but another way to support high loads/force is to use very tight tolerance bearings with thinner oils.

Anyways this appears to be religious, so I'll just leave it as my personal opinion instead of fact

Sent from my SM-G965U using Tapatalk

tolerance=/=allowance/clearance
You can even have tolerances on your allowances/clearances.

[Capt Spaulding]

Without starting a pissing match (hopefully) I'd like to ask a favor. Lots of folks toss around the term "tolerances" when discussing oils and such. Like, we need to use thinner oils because of tighter tolerances. What you're talking about are "clearances." The distances between rod bearings and their respective journals on the crankshaft are clearances. You measure them with plastigage. The allowable variation in the sizes of machined parts and the resulting differences in the clearances in various iterations of assemblies are the "tolerances." If you tolerate poor machining and widely varying measurements/clearances you have loose "tolerances." If the dimensions/clearances are held within very small fractions of each other you have tight "tolerances."

This is NOT grammarnazism - the concepts are different and it matters!! Please guys - you can do this.

[Tokay444]

Words have meanings.

[bfrank1972]

Originally Posted by Capt Spaulding

Without starting a pissing match (hopefully) I'd like to ask a favor. Lots of folks toss around the term "tolerances" when discussing oils and such. Like, we need to use thinner oils because of tighter tolerances. What you're talking about are "clearances." The distances between rod bearings and their respective journals on the crankshaft are clearances. You measure them with plastigage. The allowable variation in the sizes of machined parts and the resulting differences in the clearances in various iterations of assemblies are the "tolerances." If you tolerate poor machining and widely varying measurements/clearances you have loose "tolerances." If the dimensions/clearances are held within very small fractions of each other you have tight "tolerances."

This is NOT grammarnazism - the concepts are different and it matters!! Please guys - you can do this.

Yup, apologies, incorrect usage of words, I should get my shit together with terminology.



Clearance is concept I am addressing.



And Tokay444 excellent point on "tolerance" != "allowance".



All that said, my poor wording aside, I still stand by the fact that engine design/clearances are a major factor in determining what oil you should use, and there can be repercussions from using 50 or 60w oil in a motor with tight clearances designed for lighter weight oils. The counter arguments here seem to claim the only negative impact would be to fuel economy. There's plenty of reading out there from reputable sources supporting it's not quite that simple.

[Tokay444]

I run 0w40 year round, and at many track days in the summer.
I have no issues getting the oil above 100 degrees Celsius in the winter, and no issues with oil over heating over multiple 30 minute track sessions on even the hottest summer days.
I have over 140,000 trouble free high revving kms with the 0w40 going in at 1000kms on the ODO.
UOAs routinely suggest I could double my 8000km oil change interval, but for the cost oil 5.4 litres and a factory filter every 8000, it's cheap piece of mind.
Fuel economy has never been a number that has entered into any personal equation. Engine longevity was my primary concern when making the switch.

[ermax]

FR-S manual:


GT86 manual:



The US manual says 5W-30 is fine in a crunch but you better get it back to 0W-20 ASAP while the Euro/Asian manual says either 0W-20 or 5W-30 are fine. Same engine, same tolerances. Different countries, different environmental requirements.

[Tokay444]

And here's the Japanese manual, for the same car. Same engine. Same clearances.

[Ernest72]

Does anyone think comparing the oil and engine in the race car to our cars is a bit of a stretch. I mean no race team plans on keeping the engine running in tip top shape for over 100k miles. A race team will tear it down in the off season or maybe during the season if issues arise. That’s very different then our cars which we would like to see go forever. Plus the teams do a lot more testing related to the oil and what’s needed. The balance they need is different than our DD.

If I were tracking I would not run 0w20, but probably not 10w60 either. Best bet is to experiment and do UOA to confirm, obviously.

[TommyW]

I run an IAG Stage 1 short block with an oil cooler and their warranty states Motul 0-20 synthetic must be used to keep their warranty intact

[NoHaveMSG]

Originally Posted by Ernest72

Does anyone think comparing the oil and engine in the race car to our cars is a bit of a stretch. I mean no race team plans on keeping the engine running in tip top shape for over 100k miles. A race team will tear it down in the off season or maybe during the season if issues arise. That’s very different then our cars which we would like to see go forever. Plus the teams do a lot more testing related to the oil and what’s needed. The balance they need is different than our DD.

If I were tracking I would not run 0w20, but probably not 10w60 either. Best bet is to experiment and do UOA to confirm, obviously.

I am running Motul 300V 0-20. UOA's show 7500 oil change intervals are fine. That is mixed use, track and street.

[serialk11r]

Originally Posted by NoHaveMSG

I am running Motul 300V 0-20. UOA's show 7500 oil change intervals are fine. That is mixed use, track and street.

Wait, 7500 including track usage? Is that with an oil cooler?

[alex87f]

What's the US recommended interval for oil changes on this car?

[NoHaveMSG]

Originally Posted by serialk11r

Wait, 7500 including track usage? Is that with an oil cooler?

Yes, running an oil cooler. If you look in the UOA thread there are others who have posted similar recommendations from blackstone. I remember one of them being boosted.