08
Nov
The w in motor oil stands for winter. A gear lubricant and an engine oil having the same viscosity will have widely different SAE viscosity grade designations as defined in the two viscosity classifications.
This is because the lower viscosity oil in such temperatures will be able to circulate throughout the engine much faster than thicker.
Engine oil viscosity chart. The W in the gear oil viscosity grade is for winter grade like in engine oil viscosity. Although gear oil viscosity is not the same as that of engine oil it is rated in centistokes. But the engine and gear oil viscosity overlap.
For instance an SAE 90 gear lube is comparable in viscosity to an SAE 50 or SAE 40 engine oil. The w in motor oil stands for winter. The first number in the oil classification refers to a cold weather viscosity.
The lower this number is the less viscous your oil will be at low temperatures. For example a 5W- motor oil will flow better at lower temperatures than a 15W- motor oil. Viscosities can be related horizontally only Viscosities based on 96 VI single grade oils.
ISO are specified at 40C AGMA are specified at 40C SAE 75w 80w 85 5w 10w specified at low temperature. Equivalent viscosities for 100 210F are shown SAE 90 to 250 and 20 to 50 specified at 100C. When you see a W on a viscosity rating it means that this oil viscosity has been tested at a Colder temperature.
The numbers without the W are all tested at 210 F or 100 C which is considered an approximation of engine operating temperature. In other words a SAE 30 motor oil is the same viscosity as a 10w-30 or 5W-30 at 210 100 C. The quality of an engine oil depends on the base stock and its properties as well as on the additives.
The main requirements for an engine oil are defined temperature-viscosity properties protection against wear and corrosion keeping the engine clean holding particles like soot or abrasives in suspension yield strength under compression and. Finally motor oil cleans acids and silicon oxide from engine parts. An important factor in all these functions of motor oil is the oil viscosity.
Read on to have oil viscosity explained in simple terms. The term viscosity refers to the thickness of the oil and its resistance to flow. The viscosity of an oil is measured by its resistance to flow.
There are two numbers that define the viscosity of an oil. The first number ends with the letter W which stands for Winter. This measurement is related to how an oil flows when it is cold such as at engine start-up.
An oils resistance to thinning in hotter temperatures is called the viscosity index. Although a higher second number is good the oil also has to be robust lasting for thousands of miles until. For most machines - like car engines - the critical point of operation is at startup before reaching operating temperatures.
In cold weather lubricants with adequate viscosities at start up temperature are required. The table below indicates appropriate engine oil viscosity vs. Outside start up temperatures.
If the viscosity is too low a protecting oil film is not formed between the parts. With high viscosity too much power is required to shear the oil film and the flow of oil through the engine is retarded. Viscosity tends to decrease as temperature increases.
Viscosity index VI is a number that indicates the resistance of an oil to changes in. A gear lubricant and an engine oil having the same viscosity will have widely different SAE viscosity grade designations as defined in the two viscosity classifications. For instance an SAE 80W gear lubricant may have the same viscosity as an SAE 20W or SAE 30 engine oil and SAE 90 gear lubricant viscosity can be similar to that of an SAE 40.
The 10W-30 engine oil will have a better flow than the 10W-40 engine oil at normal operating temperature. Take a look at some internationally used engine oil grades-0W-20 This engine oil is relatively thinner when you start the engine. Here in 0W-20 the viscosity of the oil is 0 when the motor is cold.
Motorcraft Oil Quick Reference Oil Applications and Crankcase Capacities Chart Recommend Motorcraft SAE 5W-20 contd Oil Refill Qts 1 Oil Filter 2012 2013. How does motor oil viscosity work. The viscosity of an oil is measured by its resistance to flow.
There are two numbers that define the viscosity of an oil. The first number ends with the letter W which stands for Winter. This measurement is related to how an oil flows when it is cold such as at engine start-up.
The 30 reflects the viscosity grade of the oil when the engine temperature is at 212 F. If you live in a colder environment a 5W rating oil will be able to start your engine a lot sooner than a 10W rated oil. This is because the lower viscosity oil in such temperatures will be able to circulate throughout the engine much faster than thicker.
The lower the number the thiner the oil will be and the easier it will flow at low temperatures. For example a 5W-motor oil will flow better at lower temperatures than a 15W- motor oil. 5 W-20 - The W in motor oil stands for winter.
5W-20 - The number following the W refers to hot weather viscosity or how easy it will flow hot. The various types of motor oil on the market are designed for different purposes. To choose the proper type of oil for your vehicle you need to understand the significance of the oil additives viscosity ratings and classification codes.
To help the oil keep your engine cool clean and corrosion-free refiners blend in. When choosing an oil consider the range of temperature your vehicle will be operated in before the next oil change. Proceed to select the recommended oil viscosity from the chart.
For better fuel economy it is recommended to use the engine oil of a viscosity grade SAE 5W-20 API SM ILSAC GF-4. However if the engine oil is not available. This revision begins the process of extending the SAE Engine Oil Viscosity Classification system to lower high-temperature high-shear-rate HTHS viscosities by adding a new high-temperature viscosity grade SAE 16 23 mPas HTHS to SAE J300.
In addition the minimum 100 C kinematic viscosity KV100 of the SAE 20 grade is raised from 56 mm2s to 69 mm2s.