M1 0W-30 vs. 0W-20/40 Mix (S2000)

[A_Harman]

Originally Posted By: TrevorS
M1 10w30 has HTHSV of 3.0. Honda says it is suitable for all hot ambient conditions.

And people are arguing that I said M1 0w40 is thicker than necessary?

Priceless!


Honda also said that 10w30 was recommended for the best fuel economy. They didn't say that 40-weight was TOO HEAVY for the S2000.

 

[ludiferino]

Originally Posted By: 147_Grain
Suggest you run a 0W-30 in the winter and 0W-40 in the summer for this high-revving engine.

Personally, I like the blend of 0W-20 / 0W-40 year around and would use the Widman Calculator to thicken or lighten up the oil (a little) using HTHS ratios as the #1 value.


That was exactly my thoughts. Using the calculator, with the 60/40 mix, the 100 degC viscosity is ~0.3 to 1.0 cSt more than the regular M1 30s and ~0.6 to 0.8 cSt less than the M1 high mileage 30s.

BTW, I put the S2000 into storage during the winter.

Originally Posted By: A_Harman
60% of 3.8 HTHS + 40% of 2.7 HTHS will give a final HTHS of about 3.3 or 3.4, so I think you're in a good space to keep the final sheared HTHS above 2.9. If you're car has been running fine on M1 0w30, it should continue to do fine on the 0w40/0w20 blend.

Other oils I would consider would be M1 HM 10w30 or GC 0w30, but I realize this defeats your idea of only keeping two types of oil in the house.


Thanks.

I've thought about these other oils, but am looking for convenience. Also, my S2000 somehow doesn't consume any oil, so I didn't feel the need to use a high mileage oil with greater cold start viscosities. This is my first performance oriented Honda that doesn't regularly consume oil. Lastly, finding GC is a pain.

 

[HTSS_TR]

Mixing 60% M1 0W20 with 40% 0W40 is fine for S2000, HTHS is a little higher than M1 xW30. Currently I have 50-50 0W20 and 0W40 in my S2000.

I agree with OVERKILL. Back in the late 90's when Honda developed S2000 there was no shear stable conventional 5W30, and Honda didn't think that synthetic was needed, that why they recommended conventional 10W30.

Few years later they revised the oil recommendation and added 5W40 for colder climate, back then and until now there is no conventional 5W40, only synthetic. Why not synthetic 0W30 for below 0F ? Probably because when the oil get to operating temperature near the end of OCI it isn't as shear stable as 5W40.

I think Honda oil recommendation for all its vehicles is the result of extensive testing, much more than any individual can. They only require that the S2000 oil, either 10W30 or 5W40, meets API specs, it was SH, SJ back in 1999-2000.

 

[Garak]

Originally Posted By: TrevorS
Min HTHSV of a 5w40 oil is 2.9.

M1 0w40 has a HTHSV way above that.

Where are you going to find a 5w-40 with an HTHS of 2.9, or even near that? Aside from that, check a recent viscosity table, such as the latest handbook at Infineum. An HTHS of a minimum 3.5 is required for 0w-40, 5w-40, and 10w-40.

Name me one 5w-40 out there with a lower HTHS even than M1 0w-40.

 

[Shannow]

Clearly the J300 requiring a different "minimum" HTHS for the 0W, 5W, 10W was acknowledging that the spread required, with the basestocks and adds was prone to have less resistance to high shear rates than the "regular" 40s.

http://paservice.it/wp-content/uploads/2013/06/J300_201304.pdf

Now have a min of 3.5 for the 0, 5, and 10, and 3.7 for the rest.

As an aside, most of the 10W-30s (most being like 2 out of 3) around here meet A3/B3/B4, along with a couple of the 5W-30s

 

[demarpaint]

Originally Posted By: Garak
Originally Posted By: TrevorS
Min HTHSV of a 5w40 oil is 2.9.

M1 0w40 has a HTHSV way above that.

Where are you going to find a 5w-40 with an HTHS of 2.9, or even near that? Aside from that, check a recent viscosity table, such as the latest handbook at Infineum. An HTHS of a minimum 3.5 is required for 0w-40, 5w-40, and 10w-40.

Name me one 5w-40 out there with a lower HTHS even than M1 0w-40.


I was thinking exactly the same thing. I don't think it exists.

 

[ludiferino]

Originally Posted By: HTSS_TR
Mixing 60% M1 0W20 with 40% 0W40 is fine for S2000, HTHS is a little higher than M1 xW30. Currently I have 50-50 0W20 and 0W40 in my S2000.


Thanks for the application specific information. I'll try the ~60% 0W-40 based mix.