What is the difference between adding engine oil and changing engine oil?
4 Answers
Changing engine oil is to remove internal carbon deposits and sludge. Adding engine oil is to supplement the oil level when it is insufficient to meet the engine's required oil quantity. Below are specific methods for selecting engine oil for cars: 1. Performance selection: If you prioritize long-lasting oil performance, you can choose Mobil engine oil; if you focus on the oil's cleaning effect on the engine, Shell lubricants can be used; for lubricants with strong oil film toughness, Castrol is recommended. 2. Driving conditions: For frequent driving in congested areas, older vehicles, or long-distance heavy-load transportation, the viscosity of the lubricant can be appropriately increased. 3. Engine type: For naturally aspirated engines, mineral oil and semi-synthetic oil can be used. Compared to naturally aspirated engines, turbocharged engines have a more compact structure and operate under harsher conditions, requiring higher-grade lubricants with better fluidity, preferably full synthetic oil.
Having driven for decades, I know that adding oil simply means topping up the engine when the oil warning light comes on—opening the hood and pouring fresh oil into the reservoir until it reaches the proper level, a temporary fix to prevent engine damage from oil shortage. On the other hand, an oil change is a comprehensive maintenance procedure done at a repair shop: draining all the old oil, replacing it with fresh oil, and swapping out the oil filter to refresh the entire lubrication system. Adding oil is just a stopgap, like topping up when levels are low, whereas oil changes are mandatory periodic maintenance every 5,000 to 10,000 km to remove sludge and contaminants. The difference is like quenching thirst with water versus a full-body blood transfusion—topping up without changing degrades oil quality, accelerating wear and potentially leading to major repairs long-term. I also recommend regularly checking oil levels and topping up if leaking, but only consistent scheduled oil changes ensure a car’s longevity and safety.
As an average car owner, the usual scenario where I need to add engine oil is when the oil gauge shows low levels. I simply pour in a new bottle of oil myself—quick, easy, and hardly any time spent. But what about an oil change? That requires driving to a professional shop where they drain the old oil, replace it with new oil and the oil filter, which takes time and costs money. The key difference is that adding oil only focuses on the oil level, while an oil change addresses the overall oil quality—if you only add without changing, the old oil will contain contaminants like metal shavings, reducing lubrication effectiveness, potentially increasing engine noise and fuel consumption. So be smart: use oil top-ups as an emergency measure for occasional leaks, but regular oil changes, say every six months, are the proper approach. It also helps prevent issues like engine overheating, saving money in the long run. I also remind everyone to use the correct oil grade and avoid improper mixing to reduce risks.
I care deeply about vehicle safety. Adding oil is simply topping up with new oil when levels are low to prevent immediate wear, while changing oil involves completely replacing the dirty oil and filter throughout the entire oil system for a thorough cleaning. The difference between the two is as significant as taking painkillers versus treating the root cause of illness—adding oil cannot replace an oil change, because oxidized and degraded old oil reduces lubrication effectiveness. Only adding without changing increases failure risks like engine seizure. It's best to combine routine checks: top up when oil levels are abnormal, and schedule regular oil changes quarterly. This extends vehicle lifespan and ensures safer driving. I also pay attention to using the appropriate grade of oil during changes to avoid affecting performance.
