Synthetic oil or not?

Bange

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Just gotta love a good 'ole oil thread.........
Unfortunately, oil is not a question of love or hate, it is a technical question that even transcends empirical evaluations without its own instruments... and just like cigarettes, the inappropriate use of oil does not cause immediate harm, but shortens life useful or the performance of any engine.
In my car (Corsa/97), I also use an oil considered "old" (mineral base) 20W50 with API SL (the one indicated in the manual is a 20W50 SJ, which is not very easy to find around here), which I already have. 24 years and 234,500 km, without burning oil or strange noises...
I can't say anything about the oil other than that it is indicated by the automaker and has been meeting expectations, even because it was the best oil in the automaker's assessment when my car was manufactured.
 

bertsmobile1

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Ferrari oil will not turn a VW Beetle into a Porche and just cost the owners a lot more money
Using any oil above the makers specification will usually not make a tinkers curse of a difference to the engine and in many cases will cause a drastic loss of oil pressure because the old engine will have massively large oil galleries & holes where the modern thinner & substantially less viscious oil will pour out and leave journals / bushes incapable of floating the metal surfaces .
Modern oils can not stop an engine creating contaminations like acid by products of combustion, tiny carbon particles and metal part errosion debris .
The do last longer before they are compromised but mower oils should be replaced annually because a mower engine is the cheapest nastiest engine it is possible to make.
Thus using very expensive oil is in most cases simply putting lipstick on a pig .
However it does create a massive amount of amusement as masses of people who obviously have no understanding of the actual requirements or chemistry of oil get in a lather about using one oil or another .
Now if they are going into a top fueler pumping out 200Hp / litre then there is a case for arguement but a modern mower engine is lucky to be making 50 Hp/liter and way back in 1930 engines were doing better than that .
Addmittadely in the years I have been fixing mowers for a full time living I would have been lucky to have pulled more than 100 engines apart and I am yet to find one with an oil derrived failure other than from the absence of sufficient oil and in most cases , no oil at all .

But please keep it up.
I need a good belly laugh as the comedy on TV at the moment is just not funny
 

Bange

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Engine oil
OK, there is a certain logic to this, especially if the oil indicated in the manufacturer's manual contains mineral and synthetic oils or if you use a synthetic oil on an older engine, even if it has similar viscosity.
It turns out that synthetic oils are less viscous (compared to minerals), and in a cold engine the clearances are a little larger than in a hot engine, the synthetic molecules are more homogeneous and adhere more to the contact surfaces.
With these assumptions and thinking about the oil on the piston walls, a greater amount of oil remains stuck (at the inlet), and is released by the entry of the gasoline + air mixture, participating in the burning at the time of the explosion in a volume greater than the mineral, hence the greater loss.
If, on the one hand, synthetics are more efficient in lubricating and protecting parts, on the other, they are more expensive and have a higher consumption, which is not always seen in smoke... there is no way to make fried eggs without breaking eggs... .
 
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Hammermechanicman

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I go ito the auto parts store and go find to most expensive oil they have and buy that. It must be the best.?
 
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