The volume of oil in the engine: how to find out how much you need
When performing routine maintenance of a car, not all motorists know what volumes of lubricating liquids should be used.
The volume of oil in the engine of even one model may differ depending on the installed line of power units.
In this article, let’s look at how to properly measure the level in the crankcase, and accordingly, what volume of oil is poured into the engine, and why to change it at all.
In the cylinder-piston group oil lubricates, seals (allows greater compression), cools, drains combustion and wear products, and acts as a hydraulic fluid in compensators, phase shifters, etc. Oil creates the thinnest film on the surface of the rubbing parts of the engine, reducing the friction coefficient and serving to protect against corrosion or other aggressive effects of chemicals formed as a result of the combustion of fuel.
It is possible to distinguish the following main tasks and requirements to modern engine oil:
- prevention of dry friction and accelerated wear of sliding surfaces;
- reduction of heat losses caused by friction and increasing the engine efficiency;
- anticorrosive and chemical protection;
- prevention of overheating of friction pairs, removal of excessive heat;
- removal of combustion products, oxides, and microdust formed as a result of unavoidable mechanical wear of sliding surfaces;
- neutralization and dissolution of chemically active products of combustion of the fuel-air mixture, removal of soot and compounds which are formed not only on the cylinder walls but also
- seep further with crankcase gases and soot into the engine cavity.
In addition to the petroleum base component (base), many different additives are added to the engine oil. With their help, they change viscosity coefficient, temperature, and chemical resistance, neutralize aggressive compounds, and accelerated aging. Manufacturers keep the formulas and components of their additives secret.
How to properly check the oil level in the engine
No matter how modern the car may seem, it is necessary to periodically check the oil, coolant, and brake fluid levels to avoid unforeseen situations on the road. This control is under the power of any motorist.
The volume of the lubricating fluid in the engine can be determined with a dipstick. In newer cars, the dipstick’s ear or handle is brightly colored to make it easier to spot in the engine compartment. It is inserted vertically into the cylinder block opening and its lower end is lowered into the engine crankcase bath.
The dipstick itself is a long spoke with maximum and minimum marks on it. However, you must be aware of some important points in order to correctly estimate the amount of oli in the engine.
Check the level according to the following algorithm to get a correct reading:
- An important requirement is to keep the vehicle as level as possible on a horizontal surface so that the fluid in the engine crankcase is not concentrated in one corner of the tub. Avoid positioning the vehicle when it is standing on a hill or with one or two wheels on the curb. In this case, the level measurements will be incorrect.
- It is a common mistake to try to measure the level immediately after stopping the engine. For the first half-hour, after you shut the engine off, the grease will still be in the oil passages, liners, and cylinder walls. You need to wait a while until all of it drains into the crankcase pan. It happens that, seeing a low level, a frightened owner rushes to refill the fluid to the normal volume, and this leads to critical overflow of the engine with the oil. This can cause overfilling, grease squeezing through crankshaft seals or other troubles.
- Pull the dipstick out of its seating hole, wipe it dry with a rag or at least a cloth. Push it all the way back in, then take it out and inspect it. Don’t be too lazy to do this, as the dipstick may be splashed with grease and you may misjudge the level.
- Normally the level should be in the area between the two marks Max and Min. Only if the oil trace does not reach the lower mark (minimum volume) – you need to refill the oil. You can also visually inspect the condition of the oil. The most common oil – 5w40 – in warm weather will slowly collect in a drop and roll off the dipstick. For gasoline engines, the oil should not be black, but dark brown in color.
- You should refill it in small portions. Remember that due to its viscosity the oil will not flow completely into the crankcase immediately after refilling.
For older cars, it is important to check the lubrication regularly, e.g. at every refueling. By the time the insufficient oil pressure indicator lights up on the dashboard, it may be too late to refill.
Although most new cars have oil level gauges, you should not rely blindly on electronics.
It is desirable to top up when the engine is cold. The oil must necessarily be the same as it was filled at the last service or the brand recommended by the manufacturer (with identical viscosity characteristics and tolerances).
What are the dangers of insufficient engine oil volume?
When checking the engine oil fill volume, one day you may find the oil volume at or below the MIN mark. So what are the dangers of driving “low”? There are many reasons to worry. Insufficient lubrication can lead to oil starvation, in other words when less lubricant enters the friction pairs than is needed for proper operation. And the pressure sensor may not respond.
Many engines can’t tolerate driving at the minimum level for long periods of time.
You may not feel it, but such an operation slowly kills the heart of the car. The number of dry friction zones increases, and the wear and tear on parts increases. Engine cooling also worsens as the smaller fluid volume does not have time to properly dissipate heat.
An indicator or message may appear on the dashboard if lubrication pressure has dropped sharply or reached a critical minimum (some newer vehicles have separate level gauges). Stop the vehicle and measure the level 10 minutes after stopping to verify that insufficient lubricant, rather than a more serious engine problem, is the probable cause of this light.
Signs at which it is advisable to check the oil level:
- Occurrence of extraneous unusual noises with the engine running;
- A ringing tapping in the hydro-compensators of the valves;
- Increased grease temperature (many cars have a separate oil temperature indicator beside the coolant temperature gauge) or constant operation of radiator fans.
Lubricant temperature should be a few degrees below coolant temperature.
What’s the risk of too much oil in the engine
As well as underfilling, overfilling is also fraught with some problems. The excessive amount of lubricant in the engine can be caused by elementary inattention or inexperience of the master when changing the lubricant.
You may hear from some drivers a very strange opinion that more grease improves engine performance and contributes to less friction. However, this judgment is fundamentally flawed. Too much oil will cause the engine to choke. Some drivers intentionally pour more, knowing that it’s going too fast, trying to compensate for possible losses ahead of time.
If there is too much lubrication, there is increased fuel consumption. This is caused by excessive resistance to crankshaft rotation, when its counterweights can hit the surface of the fluid in the crankcase. Seemingly harmless splashing, but it can ultimately reduce fuel economy by 2-3%(!)
Consequences of exceeding the recommended volume:
- Problems starting the engine, the starter has a harder time spinning the flywheel.
- Audible hydro-compensator problems.
- Higher than normal pressure in the lubrication system.
- Accelerated wear on the oil pump.
- Heavy fouling and soot in the working area.
- Increased content of harmful substances in exhaust gases.
- Filled spark plug electrodes.
Ways to determine the required oil volume for a car engine
Each powertrain model is designed to operate with a set volume of lubricant. To find out the fill volume for your engine, you can refer to the owner’s manual or, if there is no information in the manual, search the Internet for these figures.
- Usually, the oil volumes in the instruction manual are listed in the last pages, in the tables, or in the vehicle specifications under “Lubrication system”, “Fill quantities” or “Lubricant volumes”. There you will find the values you are looking for. There you will also find a table with the recommended oil types and their equivalents.
- You can also find information on filling volumes on the Internet or on the official website of the vehicle manufacturer.
How much oil should be filled in the engine
Due to the diversity of designs, engineering solutions, engine displacement, and capacity, even engine models with similar characteristics may have different lubricant filling volumes. The manufacturer indicates the volume in the expectation that the filling is made in a new empty engine, in reality, it is impossible to completely drain all the oil without the remainder without fully disassembling the engine. This should not be forgotten.
After removal of the lubricating fluid, there will still be 0.2-0.3 quarts remaining in the engine. You can pre-determine what volume you need to buy before changing the oil, following these recommendations. For engines with a displacement of 1.6 to 2.6, 4.3 to 4.8 quarts will fit. Follow this filling algorithm:
- Initially pour 3.2-3.7 quarts into the filler neck, referring to the marks on the container.
- Wait 3-5 minutes, check the volume with a dipstick.
- If the level is still low according to the marks, add 0.16-0.21 quarts and constantly check the filling volume.
Repeat the process until the mark on the dipstick is exactly between the two marks MIN and MAX. This prevents overfilling and excessive volume in the crankcase, as it is difficult to pump back the excess. Sometimes excess oil, in addition to being squeezed out through the oil seals, will be pushed out through the dipstick seal. Also, the crankshaft counterweights can foam the oil if the level is high.
How often should I have my oil changed?
That depends on the engine and how much you drive. The interval ranges from 9 400 to 25 000 miles, depending on the make. Exact figures can be found in your car’s owner’s manual. If you drive a lot on average, i.e. 6 300 to 9 300 miles per year, you should have your oil changed about every 1.5 to 2 years.
The additives wear out even if the engine is moved very little. Some on-board computers have a function called “Engine oil life”. This shows in percent how much the oil has already worn down.
