Talk:Viscosity index

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Viscosity index improver[edit]

Viscosity index improver redirects to this Viscosity index article, but this article does not cover or even mention viscosity index improvers. H Padleckas (talk) 09:30, 18 February 2011 (UTC)[reply]

Calculation[edit]

I couldn't get the formula to parse properly in Latex, so I just left it plain-text, for someone else to do correctly. Also, I wasn't sure about citing the ASTM directly, but since my source (Engineering Tribology) reprinted the table, I just left it with the single citation.Cgirten (talk) 06:48, 6 April 2012 (UTC)[reply]

I used <math>V = 100 \cfrac{{(L-U)}}{{(L-H)}}</math>

V=100{\cfrac {(L-U)}{(L-H)}}

but your text version didn't make it clear whether the 100 was paired with the top line or the bottom line. Stepho talk 00:31, 7 April 2012 (UTC)[reply]

Explenation of L, U and H[edit]

"and L & H are values based on the oil's kinematic viscosity at 100 °C (212 °F). L and H are the values of viscosity at 40 °C for oils of VI 0 and 100 respectively, having the same viscosity at 100 °C as the oil whose VI we are trying to determine" This paragraph doesn't appear to make sense, it might be true, but I am not sure and I don't think it is very clear. I don't understand it well enough to alter it. — Preceding unsigned comment added by Gav Newman (talk • contribs) 10:41, 24 November 2015 (UTC)[reply]

The definition is certainly confusing. I rephrased the article to emphasize that L and H refer to the viscosity at 40 °C for two hypothetical other oils. The hypothetical oils have the same viscosity, U, at 100 °C and VIs of 0 and 100, respectively. tfarnham (talk) 19:41, 2 February 2021 (UTC)[reply]

Dead link, cannot find update[edit]

Under Relevance, this Typical Engine Oil Temperature Viscosity Chart link is dead. Can anyone find the updated link. I have not been able to locate it.

Wikiproha (talk) 22:00, 25 March 2020 (UTC)[reply]

Archived at https://web.archive.org/web/20191104071429/http://stmeu.com/capacitacion/wp-content/uploads/2009/05/clip_image027_thumb-5B1-5D.gif Stepho talk 22:13, 25 March 2020 (UTC)[reply]