Does oil go bad sitting in an engine?
Oil gets dirty.
But to summarize, oil does not “spoil”, and non-use certainly doesn’t sever the long chain molecules.
Yes, moisture that accumulates from combustion by-products should be vaporized off once in a while, but oil is not hygroscopic, and extended storage will not add bad things..
What happens if you go too long without an oil change?
Complete Engine Failure – If you go long enough without an oil change, it could cost you a car. Once the motor oil becomes sludge, it no longer removes heat from the engine. This can lead to a complete engine shutdown that will require a brand new engine – or a new ride – to fix.
Is it OK to add oil between oil changes?
As a rule, most engines with fewer than 50,000 miles shouldn’t use much more than a quart of oil between oil changes (unless the manufacturer says differently). … Once an engine gets beyond perhaps 75,000 miles, and certainly past 100,000, increased oil consumption should be expected.
What happens if you mix different types of oil?
The good news is that mixing different types of oil it will not harm your engine in any way in the short run. Most synthetic and semi-synthetic engine oils are based on regular oil and are compatible.
Is it OK to mix engine oil?
Mixing Motor Oil According to Mobil Oil, it should be fine to mix oils. … Many oils are a blend of natural and synthetic oils. So, if you are low on oil, don’t be afraid to add a quart or two of synthetic oil if you are using regular oil or even regular oil if you are using a synthetic.