GaryEss
Member Since: 27 Apr 2009
Location: midlands
Posts: 42
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Hello
Originally (years ago) oil was available as one viscocity grade only - Monograde oil. The viscocity index number would be a single one, i.e. 30, 40, 20 etc. during winter you would need to change your oil to one with a lower viscocity to ensure adequate circulation (thus lubrication) when cold.
Multigrade oils offer the best of both worlds. Their properties are such that they behave like a lower viscocity oil at low temp, and a higher viscocity number at higher temperature.
They are tested at 2 temperatures and the resulting viscocity number shows that , for instance, a 5w30 behaves like a 5 weight monograde during the low temp test (I believe the"W" stands for winter but may be wrong) and a 30 weight oil at the higher temp test. The actual tests are standardised by the relative industry bodies (A.P.I being one ).
So your 0 w 30 behave like a 0 weight (lower viscocity)oil when cold than you 5w 30 would but they both behave the same in terms of viscocity when subjected to the higher temperature testing.
Having a lower viscocity MAY affect the operation of your lubrication system as it 's parameters will have been designed to operate with certain viscocity of oil, (think oil pump, hydraulic lilfters etc)
Some manufacturers will also recommend different oil spec depending on market requirements or operating conditions.
Please bear in mind viscocity is but a small part of your oils specification- there are many more aspects that are needed to it's make up and these are reflected in the specifiction number. (b3, b4 etc).
As commented above if you are in warranty then stick with manufacturers spec, but further to this why change to anything else once the warranty has expired? Compared to an engine even the best synthetic oil is cheap!
Hope this helps you come to a decision
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 17th Jul 2009 4:34 pm |
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