Because the higher ambient temps lead to higher oil temps and that can thin out lower viscosity oils... so go with higher viscosity oil if you are really pushing it in the heat... but 10/30 will be adequate if not stressing the engine.mx_tifosi wrote:Why a heavier weight in the summer? My summers can get up to 120 degrees ambient. And now it's mostly city driving.ISLAMATRON wrote:...
For winter you might want a thinner oil maybe 10-30/40 or even 5-30(or 0-30). Summer, depending on the heat 15-40 should do you well... the best bet is to check your owners manual, especially with cars made by ZEE Germans.
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xpensive wrote:Lubrication, or oilfilm build-up, comes from viscosity and in xtreme cases EP-additives, nothing else.
Synthetic oils, Polyalfaoelefins, have a more favourable Viscosity Index, are more resistant to shear-breakdown and oxidation, and as a consequence gives longer lifespan of the oil itself.
But is a waste of money for my 4.6 V8 which rarely revs above 3k.
http://en.wikipedia.org/wiki/Synthetic_oil
A filter is not just a filter, what is interesting is the Reductionfactor, or "Beta" value of filtration efficiency.
Beta 6 = 200 for xample, means that only one out of 200 particles larger than 6 microns will pass thru the filter.
"Absolute filtration" in microns is a simplified guidance we sometimes use in industrial applications.
For those of you who wants to dig in I recommend this:
http://www.skf.com/portal/skf/home/apti ... 971.521015
