So, I have accumulated 4 Liter engine oil which are left overs of previous oil changes. I have accumulated these amount in 1 year. So should I use it or not? I use Mobil 1 full synthetic 0w 40.
Please give me suggestions.
If the oil is unused, and unopened, there is nothing wrong with using it.
ExxonMobil recommends a five-year maximum shelf life for engine oils, including Mobil 1™ synthetic motor oil.
Opened oil can vary in shelf life due to extreme temperature, humidity and other conditions like dusty environments. These things will shorten the life.
Yes, as Charlie says, as long as it has been stored correctly it should be fine. I generally use the leftovers from one change when I do the next so that it's not sitting around for too long - e.g. if I need 4L and I have 5L cans, I'll have 1L left, so next time I'll use that 1L, plus 3L from the next can.
A bit of a late answer here, but I would agree with the answers already posted: Yes, you can definitely use it. That being said, I would not recommend storing engine oil for more than a few years, since the additives in the oil can begin to settle out of the oil.
Store it, as already said, in a dry location with fairly stable temperature and humidity, but don't hold on to it for 5-10 years: engine oil does eventually break down.
Yes you can, and you might decant it into smaller containers for top ups on the road. In summer you do not want too much air as considerable vapour pressure can build up. It is common on farms and anywhere plant is maintained to buy in drums. It is too expensive to waste.