How can you tell the difference between synthetic motor oil and traditional petroleum-based oil?

Question

I always like to get synthetic motor oil in my car. Maybe I'm just paranoid, but I fear that my mechanic is charging me for the synthetic price and putting plain old petroleum-based oil in my car. Is there some way I can tell the difference between the two? Can I take a drop of oil off the dipstick and run some sort of simple test on it? I would prefer not to have to pay for an official test.

Answer 1

Sure. Take some of the oil in your car and an equal size sample of the real synthetic oil your mechanic says he put in your engine, and put them in your freezer (zero degrees F.) After a few hours of chilling them, see which one pours faster. Synthetics pour faster at cold temperatures.

Answer 2

First of all you shold read the ownwer´s manual and check if is needed to use synthetic oil in your car. That´s to important, because the internal parts and the regular regime of the engine are made to run with a specific kind of oil. If you use a diferent type you can cause severe damage to the engine. Some parts that suffer with this mistake, are: gaskets, seals, rings, and much more. With you have a doubt about your´s mecanic, you can call the manufactor of the oil. I´m sorry about my english its a kind of rusty. I´m from Brasil. I wish i could help you anyway.

Answer 3

No way to tell with "naked-eye"because the difference is that all the molecules in synthetic are the same size,because it is produced in a "lab",mineral oil has varying sized molecules because it is produced by nature

Answer 4

you can't see with naked eye between different oil. You need to sample it and send it way to a lab.