2006-11-04 18:23:24 · 3 answers · asked by ahmad g 1 in Science & Mathematics ➔ Chemistry
Simple, get an engine and put fresh oil in it. Run the engine until it seizes up and stops running. The time the engine ran is the useful life of the oil. Seriously, engine oil life is calculated by subjecting engine oil to contolled tests, and then measuring breakdown byproducts and changes in mechanical/chemical makeup. From this a life expectancy under these conditions can be calculated.
2006-11-04 18:53:04 · answer #1 · answered by thewizardofodd 3 · 0⤊ 0⤋
When a car is run cold right after start up it produces sludge, acids, and other impurities in the engine oil. After several starts and stops these build up.
It is true that engine oil drops slightly in viscosity after being run several 1000 miles, but the build up of sludge, acids, and other impurities make the oil "dirty". Dirty oil is what can damage an engine the most. This is one reason why oil looks black when it is being changed. The oil itself is still mostly the same, only now it has additional unwanted stuff in it that can cause engine damage.
A car used mostly for going short distances needs more frequent oil changes than a car used mostly for highway driving.
2006-11-05 06:37:07 · answer #2 · answered by Bob 5 · 0⤊ 0⤋
Drop in viscosity is noticed as the oil is used. Synthetics hold their viscosity for much longer than natural oil.
You need to monitor viscosity at different temperatures (anywhere from 0-100 Celcius) selecting 0,25,40,60,100 and plot the curve and see how the viscosity curve shifts as the oil ages.
2006-11-04 18:56:26 · answer #3 · answered by Stonerscientist 2 · 0⤊ 0⤋