Coefficient of Friction

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Nov 16, 2002


Red Line also will reduce lubricant temperatures significantly. Track testing done by the Delco Chassis Division of General Motors showed a reduction in both engine and transaxle temperatures of at least 30 degrees F when comparing Red Linemotor oil and to a major synthetic brand. These tests were performed in a Oldsmobile Calais and a Chevrolet Berreta GTZ equipped with the High-Output QUAD 4.

According to this link that I found on BITOG, Redline has 1/2 the Cf of Mobil 1. What makes an oil have better Cf then another and is this the mechanism that causes some to see lower engine temps when using a different brand of oil such as RL or Amsoil S2k? I would guess that these oils contian more FM's then the other oils so less friction is produced and therefore less heat? Is this a correct assumption? Thanks

[ October 26, 2003, 08:17 PM: Message edited by: buster ]
This is an awesome question because everyone thinks that friction is automatically a function of viscosity.

I have found that some oils perform better than others with respect to this "slipperiness" factor. For eg., I too have found that Syntec 5-50 and the TWS 10-60 are more slippery (have lower coefficient of friction) than M-1 wonder eveyone thinks 50 weights are thick.

That is why a lower coefficient of friction is more important than picking a thinner grade when it comes to producing more power (without the expense of protection) and fuel economy.
Just a note, my car is running very smooth with RL. In fact it feels faster and it is definitley quieter. I don't think it's all in my head either. I usually don't believe these things but I really do think it has made a difference.
I did by Amsoil, but it's still in the wife's trunk. I went ahead and ordered 5qts of RL to try out. I couldn't resist. After I sample RL, I will have tried Amsoil,M1 and RL. Hopefully I can pick ONE oil to stay with. My car is a test machine so when I buy my next car/truck I wont have to do this. It's just a Corolla so I don't mind. Tough little car though.
How about I send you 6 litres of Petro Can Duron 5W40 for free?
You know, just to let you see what an engine oil is supposed to perform like.
I posted about my friend having the same experience getting cooler temps switching from M1 15W-50 to ARO 20W-50 a few months ago upon joining and had a different response that time?
Now I know it isn't scientific or anything as put in the other thread, but just a comparison during the immediate period before/after change during roughly similar weather conditions, etc.;f=1;t=002339

[ October 28, 2003, 12:01 AM: Message edited by: Gary ]
This is something that i have mention in an other thread ..anyway was exactly 2 years ago(late october) when i switched from mobil 1 15W50 to motul 300V 10w40(100% ester racing oil,HTHS 3.93) because i was afraid that mobil would be thick for the winter. Well i was wrong, a couple of days after the change i noticed a small power loss and a more rough idling. The 300V behaved in a way that made mobil look thinner!!..apparently the motul had less friction modifiers??
The other thing that impressed me was the great heat transfer of the 300V. There is a beautiful road in the mountains 6 miles from the town i live.
Great tarmac and the most important almost deserted. It is 20 miles to the top and when i arrive to the top ,the hood of the car is always burning(10W40 blend,5W40 synth,15W50 synth).
BUT it was cold with the motul!!!
Do esters have such a great heat transfer..?? i came to the conlusion that ..yess!! and what about the coefficient of friction that was worst with motul??? and better with mobil?

That is why a lower coefficient of friction is more important than picking a thinner grade when it comes to producing more power (without the expense of protection) and fuel economy.

I completely agree. I bring this up because my friend runs S2k in his vette and Tahoe and noticed 10-20 degree temp. drops. IMO, this is a real plus. If I had a Vette and I could get temps to drop that much, I'd feel much better. Excessive heat and dirt are an engines worst enemy I would think. Even if wear was the same with another oil, I'd chose the one with a better coefficient of friction.

With that being said, RL and S2k most likely have more esters and FM's then your average ASL/ATM/M1 oil. The price I also think reflects this. RL I believe has the lowest coefficient of friction among all oils. S2k I would guess is low too. On a hot summer day if my car ran 15F lower with a certain oil, I'd be very happy with that.

[ October 27, 2003, 01:35 PM: Message edited by: buster ]
Yannis, in your post you claim that the engine was "cold" because of the oil you used? Combustion was still taking place and the engine temperature is determined by the cooling temperature, capacity and efficiency. Some temperature change may have been possible, but unless you can tell the difference between a couple degrees at 150C, you're a better man than I am...

Secondly, you claim that the Motul 10-40 made "M-1 look thinner". If M-1 15-50 was thinner and thinner oils are 'better' coolers, then why would the Motul feel cooler?

Maybe on both accounts, you're experience was during a colder time of the year...winter? Colder temps may make the Motul seem thicker...and the engine colder after the same amount of kms...

When I was referring to coefficient of friction, I'm not sure how temperature comes into play. The engine temps are determined by the cooling system...not the oil! Oil temperature is another story, however, not many of us have an oil temp. guage and I've never heard of viscosity to blame for a 'high oil temp'. If the oil temps are high eg. racing/towing/extended uphill driving, then you may need an oil cooler...not a more/less viscous oil.

However, my point being that I have noticed some "higher" viscosity oils that perform better with respect to power and economy than thinner a 60 weight performing better than a 50 weight due lubricant "quality" differences.
Dr.T, enigne oil is responsible for either 40% or 60% of engine cooling. (not sure which). RL has the lowest coefficient of friction of all oils made. Probably due to all the moly. Anyway, I've never noticed a difference in how my engine ran until I've used RL. Amsoil S2k, and all the M1 grades ran the same. RL however has made a very noticeable difference. M1 0w-20 had a nice light feel but RL seems to have quieted down my engine and give me more HP.

Originally posted by Dr. T:

Secondly, you claim that the Motul 10-40 made "M-1 look thinner". If M-1 15-50 was thinner and thinner oils are 'better' coolers, then why would the Motul feel cooler?

It is confusing ,that's why i used the
It was my first climb with the 300V ,still late october and i had pushed really hard,that's why i still remember it like yesterday. I go there at least twice a month so there were 5-6 more runs with motul with similar results ,but i don't remember them so clearly .Maybe the colder weather
made think the same way you did ...

Within these 2 years i have used 3 different oils bp 7000 15W50, mobil semi 10W40 ,and lately opel's 5W40 .Winter-summer none of these oils managed to imprese me like motul and as i told you i go there twice a month.
I am going to use it this summer again.
For anyone thinking of using RL, I must say the low Cf, which according to Roy Howell a few years back is 1/2 that of Mobil 1, really makes a difference. My car has absolutely picked up a few HP. The car hardly has any to begin with
so when I do gain a few, it's noticeable. I have never had an oil make that much of a difference in how my car runs.

If that were true, you should have seen a noticable increase in gas mileage....

So have you and how much?

TS, I've picked up approx. 2mpg on average. I havn't been able to test enough to say for sure, but this bc I'm in the process of moving so my driving conditions have not been the same. With the increase in HP, that I am assuming, I've also been driving a bit faster which can offset the increase in MPG. I'll keep track this week and see what I end up with.

[ November 02, 2003, 11:53 AM: Message edited by: buster ]
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