Is there some engine oil left during car maintenance, can it still be used next time?

The amount of oil required for car maintenance is mostly not a whole number. Adding 4 or 5 liters of oil is just right, not much, not much, only a few models are whole numbers. Most cars have 3.7-liter, 3.8-liter, 4.5-liter, and so on, with a large bucket of engine oil costing 4 liters and a small bucket costing 1 liter. Some cars can't finish a big bucket, some cars can't finish a big bucket and a small bucket, and no matter what, there must be a little left. It's a pity not to do it anymore, it's also a waste. Taking it away may not save enough for a while, and I'm afraid it will exceed the shelf life. Can the remaining engine oil be taken away and stored for future use?

It is completely possible. Take it away and store it for future use, but make sure that the oil used each time is the same. Different brands and models of oil should not be mixed as much as possible. It is suitable for car owners who always go to 4S stores for maintenance or have a fixed maintenance location. In practice, few people take away the remaining oil. Generally, after maintenance, they drive away directly, leaving the remaining oil and old parts in the repair shop. Taking away the engine oil is often troublesome, and it has to be kept in the trunk to take up space. The main reason is that it takes a long time to accumulate enough oil for a maintenance, and when it is accumulated enough, it has already passed the shelf life. Many people think this way.

The issue of shelf life is indeed something to pay attention to. The shelf life of unopened engine oil is relatively long, usually three to five years. But the shelf life after opening the seal varies depending on the storage method, and even after being well preserved, it can reach three to five years. The deterioration of engine oil after opening the seal is mainly caused by poor sealing. Some chemical components in the engine oil will react with water in the air, ultimately leading to the deterioration and failure of the engine oil. So the storage of the remaining engine oil is crucial. First, seal the bottle mouth with cling film, and then screw on the bottle cap to avoid any problems. It's also very simple. It's best to take it home and place it in a cool and dry place, and then take it back to the car when using it. Do not keep it in the trunk all the time, as it needs to be stored for a long time. The oil in the trunk will shake continuously with the bumps of the car, which can accelerate deterioration.

Even if there is 0.5 liters left after each maintenance, it takes eight times to save up to 4 liters. If the car is driven very little and the maintenance frequency is low, it takes several years to save up to 4 liters. So there are also tricks to using the remaining oil. For the second maintenance, add the remaining oil from the first maintenance first, and then add new oil. This way, all the remaining oil is new, and so on for the next maintenance. This way, the remaining oil for each maintenance is new, which can avoid prolonged storage time and greatly reduce the risk of oil spoilage.

Whether the engine oil has deteriorated can generally be determined by smelling the odor and looking at the color, but it requires some experience. It is difficult for individual car owners to judge, and experienced maintenance workers who have more exposure to engine oil can make the judgment. The odor is unpleasant, or there is a sour smell indicating that the engine oil has gone bad, and a darker color can also indicate that it has gone bad. The comparison of colors should be compared with the same type of engine oil, as different types of engine oil have different colors and brightness. It is possible to use the remaining oil from the previous maintenance first, without the need to determine whether the oil has deteriorated, because maintenance is required every six months, and even if it is not well preserved, it will not spoil, after all, the time is short.

From：WONDEE Autoparts

2024-6-21