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Oil Viscosity
thepest - 16/9/08 at 05:44 PM

I'm trying to understand the SAE figures, I did a wiki search and I know what the 10W-30 means.
At the moment I am running 15W40 oil in my car, if I used 15W60, then does that mean I will have more oil flowing through the engine at high temp because the viscosity is less or does it mean just the opposite?

britishtrident - 16/9/08 at 05:49 PM

quote:
Originally posted by thepest
I'm trying to understand the SAE figures, I did a wiki search and I know what the 10W-30 means.
At the moment I am running 15W40 oil in my car, if I used 15W60, then does that mean I will have more oil flowing through the engine at high temp because the viscosity is less or does it mean just the opposite?


Less when hot --- a lot depends what engne your running but a 15w/60 should be fine for most engines in the Maltese climate,

meany - 16/9/08 at 05:50 PM

i find this valvoline link explains it well.

http://www.valvoline.com/carcare/articleviewer.asp?pg=ccr20040601ov

failing that, there is a guy who frequents car forums going under the name of "oilman", i dont know if he is on here though.

Paul TigerB6 - 16/9/08 at 05:51 PM

The second number relates to viscosity at higher temperatures - the higher the number the more viscous. A 15W60 will help maintain more oil pressure at higher temps in a harder worked engine and so more suitable for a race engine etc.



Editted to say - Didnt see you were in Malta and so higher average temperature to your climate. As BritishTrident says though - less flow at higher temps but as above it will help maintain more oil pressure. I too would agree that 15W60 would be better for your much warmer climate as your oil is likely to run warmer than here in the UK

[Edited on 16/9/08 by Paul TigerB6]

thepest - 16/9/08 at 07:49 PM

Cheers guys, thanks a bunch. Clearer now.