What are the five oils and three fluids?

[OGraham]

The five oils in 'five oils and three fluids' refer to: engine oil, transmission fluid, fuel, brake fluid, and power steering fluid. The three fluids refer to: windshield washer fluid, coolant, and battery fluid. Engine oil: Its main function is lubrication, along with cooling, sealing, rust prevention, and shock absorption. The replacement interval mainly depends on the oil type. Conventional mineral oil can be changed every 5,000 kilometers, while synthetic oil can be extended to 8,000 to 10,000 kilometers. Transmission fluid: Transmission fluid is used to lubricate and cool the transmission. It is generally recommended to replace it every 60,000 kilometers. Fuel: Fuel lubricates and cools the engine, protecting it. When the oil level is low, it must be replenished promptly. Brake fluid: As the name suggests, it transmits pressure evenly during braking to achieve braking. It has four main functions: energy transmission, heat dissipation, anti-corrosion and rust prevention, and lubrication. Power steering fluid: A special liquid used in the car's power steering pump. It is generally recommended to replace it every 30,000 kilometers. Windshield washer fluid: Cleaning water for the wipers. In principle, tap water can be used, but sediment in homemade washer fluid may clog the nozzles. Battery fluid: Most cars on the market today come with maintenance-free batteries that do not require water addition. To check the battery, simply look at the color in the inspection window to determine its condition. Coolant, short for antifreeze coolant, is a cooling liquid with antifreeze properties. It prevents the coolant from freezing and expanding in cold winter conditions, which could crack the radiator or damage the engine block or cylinder head.

[DiJace]

In my daily driving, I pay special attention to the 'five oils and three waters,' which are the basics of car maintenance. The five oils refer to engine oil, transmission oil, brake fluid, power steering fluid, and clutch oil (or differential oil), each responsible for lubrication and functional operation. Insufficient engine oil can cause overheating and severe wear, while a lack of transmission oil leads to rough gear shifts. The three waters are coolant, windshield washer fluid, and battery fluid. Coolant prevents overheating and boiling over, washer fluid keeps the windshield clean for clear visibility, and battery fluid is mostly obsolete in electric vehicles but still relevant for conventional cars. I check the fluid levels every quarter—just a quick peek under the hood—to avoid breakdowns and costly repairs. Don’t underestimate this routine; neglecting it can lead to engine failure or accidents. Making it a habit ensures safety and peace of mind.

[RyleeFitz]

From experience, the five oils and three fluids are the lifelines of a car. Engine oil ensures smooth engine operation, transmission oil protects gears and reduces wear, brake fluid guarantees timely braking response, power steering fluid helps with easy steering, and differential oil lubricates drive components. Among the three fluids, coolant prevents freezing and boiling, washer fluid keeps the view clear, and battery fluid, though less common in modern cars, needs replenishing in older models. I recommend a monthly self-check—just ensure the levels are within the normal range, as both too low and too high can cause issues. For example, leaking coolant can lead to engine failure, and insufficient brake fluid increases the risk of brake failure. Timely top-ups and replacements extend part lifespan, save on major repair costs, and make driving safer and more comfortable.

[LeAlyssa]

Paying attention to the five oils and three fluids is directly related to driving safety. Lack of engine oil can cause the engine to seize, while insufficient transmission oil may lead to gear dragging. Low brake fluid is very dangerous as it can cause brake failure. A shortage of power steering fluid makes turning the wheel laborious. Insufficient coolant can easily lead to overheating and cylinder explosion. Low washer fluid makes it hard to see the road clearly, increasing the risk of accidents. Regular checks are simple—just open the caps to ensure the color and levels are normal. I check them every two refuels. Don’t delay—safety first can prevent accidents.

[McAdalynn]

From a cost-saving perspective, the maintenance of five oils and three fluids is crucial. Regular oil changes save fuel and extend engine life, while aged transmission oil must be replaced to prevent component damage. Leaking brake fluid or coolant can lead to costly repairs. The three fluids, like washer fluid, are minor expenses but ensure safe visibility. I personally check them by opening the hood to inspect fluid levels, topping up when necessary to avoid major repair costs. Small investments like these can save thousands in repairs—why not do it?

[VonMaverick]

Think of a car as a living being, where the five fluids and three waters are its blood and bodily fluids. Engine oil acts like blood, lubricating the organs (engine); transmission fluid aids flexible limbs (gear shifting); brake fluid ensures strong legs and feet (braking); and power steering fluid allows for nimble turns. Among the three waters, coolant functions as a sweating system to dissipate heat, washer fluid is like tears cleaning the windows, and battery fluid serves as an energy source that older cars may need replenishing. Neglecting them will cause the body to break down, so regularly checking the engine bay is like getting a health check-up. Beginners need not panic—simple maintenance ensures your beloved car keeps running smoothly for years.