15w40 flash point

[jorton]

Why are Delo 400 and Longlife so different when they're both 15w40? VII numbers are about the same. Delo 400 is 230(446) Longlife is 205(400)

 

[labman]

Flash point doesn't tell you much about a complex solution like a modern motor oil except how you have to label it to ship it. If one of the components was added as a little solution in a relatively volatile solvent, it would depress the flash point while having little effect on the properties of the oil.

 

[wwillson]

Labman, I've always want to ask: What is the definition of "Flash Point" and "Fire Point"? Thanks, Wayne

 

[labman]

Flash point is the temperature where something will catch fire when you hold a flame over it. Add a little acetone to anything, and the flash point will drop drastically. Well maybe not ether. Tag and Cleveland are the 2 most common methods for measuring flash point, and I think both have open cup and closed cup. Confining the vapors in a closed cup system results in lower flash points. Fire point is when you see the whites of their eyes.

 

[wwillson]

quote:

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Originally posted by labman: Flash point is the temperature where something will catch fire when you hold a flame over it. Add a little acetone to anything, and the flash point will drop drastically. Well maybe not ether. Tag and Cleveland are the 2 most common methods for measuring flash point, and I think both have open cup and closed cup. Confining the vapors in a closed cup system results in lower flash points. Fire point is when you see the whites of their eyes.

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Thanks for the info! >Fire point is when you see the whites of their >eyes. Cute!

 

[TallPaul]

quote:

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Originally posted by jorton: Why are Delo 400 and Longlife so different when they're both 15w40? VII numbers are about the same. Delo 400 is 230(446) Longlife is 205(400)

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In general the thinner oils have lower flash points. My understanding of flash point is the temperature at which the oil gives off sufficient vapor that the vapor ignites when exposed to an open flame. Given that, it would seem that there should be a correlation between flash point and oil volitility as experienced in oil consumption through vaporization. The lower the flash point, the more it seems would the consumption be. When the oil volitizes like that, I suspect it leaves behind residue, perhaps creating sludge? Of course flash point is only one of many parameters to look at when selecting an oil. Nonetheless, I prefer higher flash points. One reason I like Valvoline Maxlife 10w40, which has a listed flash point of 242(468). [ April 25, 2004, 12:16 AM: Message edited by: TallPaul ]

 

[69 Riv GS]

TALL PAUL: I agree with you. It seems like a higher flash point results in a lower NOACK %.