You can easily determine the very best oil through this very simple test.
First you need to select oil samples, let’s say the top 30 selling products. Since you want your results to be statistically significant you’ll want to test these oils in a variety of engines, let’s say the top 30 selling engines, and assign 10 engines for each oil. Assuming some engines will drop out of the test for some reason you’ll want to increase the engines by 10%, so let’s say an even 10,000 engines.
Next, disassemble all of the engines and carefully measure them for wear, clearances, varnish, piston deposits, and sludge, and then reassemble the engines and add the oil,
Next run each of the cars for 10,000 mile OCIs with identical mixed driving environments, including speeds, terrains, idling time, ambient temperatures, and fuel quality.
Finally, disassemble all of the engines and re-measure them for wear, clearances, varnish, piston deposits, and sludge. Then feed all of the data into a computer and have it rank the oils.
The oil at the top of the list is the very best!
Oh, and since oil formulations and engine designs change on a regular basis, be sure to repeat this test before each oil change.
Alternatively, you can buy an oil that is certified to meet all of the specifications set by your engine manufacturer, but that’s no fun.