Originally Posted By: CATERHAM
Originally Posted By: Brons2
Originally Posted By: CATERHAM
Originally Posted By: buster
My car is spec'd for an oil with a HT/HS of 2.6-2.9. I'm using a 3.3 now. I'm just going to add M1 0w20 for top up oil over the course of 10k+ miles.
RL 5W-20 is similar in many ways to M1 HM 5w30 having the same HTHSV and therefore the same hot operational viscosity and a robust add' pack. But it will actually be thicker on start-up due to it's considerable lower VI of 145.
This post doesn't pass the smell test.
RL5w20 vis@ 40C 55cSt vis@100C 9.1 vis index 145 HTHS 3.3
M1HM 5w30 vis@40C 69.2 vis@100C 11.7 vis index 165 HTHS 3.3
SOURCES: Manufacturers' product data pages
http://www.redlineoil.com/content/files/tech/Motor Oil Product Data.pdf
http://www.mobil.com/USA-English/Lubes/PDS/NAXXENPVLMOMobil_1_High_Mileage_Oil.aspx
A cold startup after work for me in the summertime is often around 40C. So you're telling me that RL 5w20 is actually thicker at that temp? Sorry, not buying it.
Your obsession with VI and HTHS is clouding your mind, I am afraid. I am happy that Toyota 0w20 works great in your Caterham at the track. But for most low stressed, daily driven vehicles, especially in a mild climate like mine, these numbers do not come into play that often.
Furthermore, what qualifications do you have to make the claims that you do on BITOG? Are you a tribologist? Oil blender? Chemical engineer? If you are none of the above, then I say that your opinion is no better than mine, and I say 55cSt is thinner than 69.2Cst.
thanks.
What you don't understand is that kinematic viscosity (KV100) doesn't correlate very well with operational viscosity in an IC engine but HTHSV does very well. The best proxy for operational viscosity is the oil back pressure that an oil pressure gauge measures.
Anyone who has run RL 5W-20 know just how heavy this oil is.
I've run it and it's heavier than M1 5w30 and PP 5w30, especially so on start-up.
I posted a comparison of about a dozen different oils based on oil pressure in the following thread:
https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2276634&page=1
Can you not read your own posts? You said, it would be thicker at startup. I said, that's impossible, and I stand by what I said. M1HM 5w30 will not be thinner than RL 5w20 at any start up temperature you are likely to see on the North American continent.
thanks.
p.s.: You don't mention your qualifications, either.
Originally Posted By: Brons2
Originally Posted By: CATERHAM
Originally Posted By: buster
My car is spec'd for an oil with a HT/HS of 2.6-2.9. I'm using a 3.3 now. I'm just going to add M1 0w20 for top up oil over the course of 10k+ miles.
RL 5W-20 is similar in many ways to M1 HM 5w30 having the same HTHSV and therefore the same hot operational viscosity and a robust add' pack. But it will actually be thicker on start-up due to it's considerable lower VI of 145.
This post doesn't pass the smell test.
RL5w20 vis@ 40C 55cSt vis@100C 9.1 vis index 145 HTHS 3.3
M1HM 5w30 vis@40C 69.2 vis@100C 11.7 vis index 165 HTHS 3.3
SOURCES: Manufacturers' product data pages
http://www.redlineoil.com/content/files/tech/Motor Oil Product Data.pdf
http://www.mobil.com/USA-English/Lubes/PDS/NAXXENPVLMOMobil_1_High_Mileage_Oil.aspx
A cold startup after work for me in the summertime is often around 40C. So you're telling me that RL 5w20 is actually thicker at that temp? Sorry, not buying it.
Your obsession with VI and HTHS is clouding your mind, I am afraid. I am happy that Toyota 0w20 works great in your Caterham at the track. But for most low stressed, daily driven vehicles, especially in a mild climate like mine, these numbers do not come into play that often.
Furthermore, what qualifications do you have to make the claims that you do on BITOG? Are you a tribologist? Oil blender? Chemical engineer? If you are none of the above, then I say that your opinion is no better than mine, and I say 55cSt is thinner than 69.2Cst.
thanks.
What you don't understand is that kinematic viscosity (KV100) doesn't correlate very well with operational viscosity in an IC engine but HTHSV does very well. The best proxy for operational viscosity is the oil back pressure that an oil pressure gauge measures.
Anyone who has run RL 5W-20 know just how heavy this oil is.
I've run it and it's heavier than M1 5w30 and PP 5w30, especially so on start-up.
I posted a comparison of about a dozen different oils based on oil pressure in the following thread:
https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2276634&page=1
Can you not read your own posts? You said, it would be thicker at startup. I said, that's impossible, and I stand by what I said. M1HM 5w30 will not be thinner than RL 5w20 at any start up temperature you are likely to see on the North American continent.
thanks.
p.s.: You don't mention your qualifications, either.
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