Viscosity and temperature lubricant viscosity decreases dramatically with increasing temperature loglog x relationship viscosity index v. Viscosity is a tensorial quantity that can be decomposed in different ways into two independent components. This publication describes the api engine oil licensing and certification system eolcs, a voluntary licensing and certification program designed to define, certify, and monitor engine oil performance deemed necessary for satisfactory equipment life and performance by vehicle and engine manufacturers. When you see an oil thats rated sae 30, this translates into an engine oil that has a viscosity between 9. This provides a measure of an oils ability to flow to the engine oil pump inlet and provide adequate engine oil pressure during the initial stages of operation. Multigrade oils sometimes it gets much colder than room temperature particularly during the winter.
It should be noticed that there is no relationship between the sae engine oil and gear oil classifications. Engine oils approved to the dexos specification will on show the dexos symbol the container. Kinematic viscosity is the dynamic viscosity divided by the density typical units m2s, stokes, st. This helps with oil flow at initial startup, because having a 30 grade oil at startup in the winter is much too thick. Viscosity 5 viscosity coefficients viscosity coefficients can be defined in two ways. For example, at room temperature, water has a dynamic shear viscosity of about 1. Production of diesel fuel from used engine oil is involving. Use of engine oil that is approved to the dexos specification or an equivalent engine oil the appropriate viscosity grade. The oil helps in reducing friction in the engine and removes all dirt and filth from the machineries. Mystik heavy duty product line manager mark betner breaks down the basics of engine oils and viscosities and helps you to determine whats best for. One of the consequences though of lowering oil viscosity is a decrease of the minimum oil film thickness. Motor oil, engine oil, or engine lubricant is any of various substances comprising base oils enhanced with various additives, particularly antiwear additive in addition to detergents, dispersants and, for multigrade oils, viscosity index improvers. Some oils break down and significantly increase in viscosity after extended periods of hightemperature operation. Page 37 periodic maintenance 27 torque and locking agent torque fastener remarks nm kgfm ftlb engine lubrication system.
Is there any benefit using the higher viscosity and burning less, like to the cat converter. Pdf this article focuses on temperature relations of dynamic viscosity for selected engine oils. Us9085743b2 low viscosity diesel engine oil composition. Motor oil includes additives developed to reduce changes in viscosity because of temperature. Oils without the letter w, intended for use at higher temperatures, are based on the viscosity at 100oc only. An examination was made on the effect of lowviscosity engine oil on fuel efficiency improvements and engine reliability for the purpose of improving fuel efficiency through the use of select engine oils. This revision changes the cold cranking simulator ccs viscosity limits in sae j300 from critical to noncritical specifications, as defined in astm d3244. The lower the viscosity, the less energy it takes to shear the oil and the cooler the oil, but conversely, the lower the viscosity, the thinner the oil film. The role of engine oil viscosity in low temperature cranking and starting, volume 10 presents the methods for measuring the low temperature viscosity of engine oils that would correlate with the coordinating research council crc engine test results. Put simply, viscosity is the most important property of a lubricant. It is mostly used to characterize the viscositytemperature behavior of lubricating oils.
Pdf lowerature behaviour of the engine oil researchgate. These changes can cause exces sive oil consumption, engine deposits, accelerated wear and difficult coldstarts. Because it is important to lubricate the engine, it is necessary to start working quickly and low viscosity helps to do it when it is cold. Resists oil breakdown xl synthetic motor oil maintains its fluidity viscosity under the most extreme conditions. Car engine oil car engine oil helps in lubricating the internal parts of the car, such as piston cylinder walls. Viscosity arising due to internal molecular friction produces the frictional drag effect. Adjusting the oil and oil filters is very important so that the vehicles engine is functioning properly. Multigrade oil satisfies the viscosity requirements of one of the w grades at low temperatures and one of the nonw grades at high temperature. What is oil viscosity, and why is it important to me. Oem members of the engine oil viscosity classification eovc task force have advised the task force that modern engines can start at viscosities above the current ccs limits in j300.
Ideally, an engineer would prefer the oil viscosity to remain the same when the engine is hot as when it is cold. Due to scarcity of petroleum products, the used engine oils can be used in engine as engine oil after purifying it. Effect of low viscosity oils on engine bearings dr. In lab testing 10w30 synthetic smallengine oil reduced oil consumption 61 percent compared to three leading 10w30sae 30 motor oils. In race engine, parts would not last with metal to metal contact. The viscosity index vi is an arbitrary, unitless measure of a fluids change in viscosity relative to temperature change. High temperature dynamic viscosity sensor for engine oil.
Now i live in south california and per the manual i wont need the 5w30 for the most part. The sae wanted a system that reflected the suitability of an oil for use as an engine lubricant and was easy for the consumer to understand. Study of lowviscosity engine oil on fuel economy and. An engine oil composition that has lower viscosity then the lowest viscosity grade specified by the current standard sae society of automotive engineers viscosity classification and achieves excellent abrasion resistance under conditions of high temperature and high shear rate without an increase in the amount of antiabrasion agent, said engine oil composition characterized by the. For this reason the society of automotive engineers sae, in cooperation with engine manufacturers, developed a classification system for motor oils based on viscosity measurements. Failure to use the recommended engine oil or equivalent can result of provider. Influence of engine oils dilution by fuels on their viscosity, flash point. Simply put viscosity is a physical property of a fluid or gas that reflects its tendency to flow. The main requirements for an engine oil are defined temperature viscosity. Understanding the sae motor oil viscosity standard what is motor oil viscosity. If i use 5w30 it burns 1qt1km, if i put 10w30 it burns 2qts3km. Even at this early stage, viscosity was recognized as one of the most important characteristics of an oil. Effect of low viscosity oils on engine bearings substech.
Kinematic viscosity is merely the time it takes a quantity of the oil at the specified temperature to flow through a certain orifice. Sae j300 is a viscosity classification for engine oils, and sae j306 is for axle and manual transmission lubricants. The role of engine oil viscosity in low temperature. They consist of mineral, semi or fully synthetic base oil base stocks plus a varying number and amount of additives. Types of motor oil how to pick the right engine oil. Article information, pdf download for shear rates in engines and. The engine oil composition of the present invention has a lowtemperature viscosity the fuel efficiency of the engine oil is improved, when the engine oil composition with an improved low. Hths viscosity is a very different measure than the kinematic viscosity measures in centistokes. Rocker shaft oil pipe bolts 87 inlb cylinder head oil pipe banjo bolts oil filter 17. Shear rates in engines and implications for lubricant design ri.
Fuel efficiencyimproving effects were estimated by. This is the basic challenge engineers face when designing engine lubrication. Follow the instructions displayed in the setup wizard. Certain motor oils are designed to be thinner less viscous when cold and more viscous thicker when hot.
With proper planning and a high performance engine oil that doesnt compromise on engine protection, switching to lower viscosity engine oil has the potential to yield excellent returns for fleets and drivers alike. What is engine oil viscosity firestone complete auto care. So on my 95 galant the oil consumption is creeping to the higher range. Extensional viscosity, a linear combination of shear and bulk viscosity, describes the reaction to elongation, widely used for characterizing polymers. Viscosity of engine oil viscosity table and viscosity. Lubricants and lubrication from the well to the applications. Guide to measuring oil viscosity 2 measuring kinematic viscosity gravimetric capillary the most widely used technique for measuring kinematic viscosity is the use of a gravimetric capillary that is temperature controlled, usually 40 c for single grade oils, and both 40 and 100 c. An oil additive named startech made by cmw oil company proprietary for north star automotive group was tested via dynamometer trials and was found to produce higher horsepower and torque. We commonly refer to high viscosity fluids as being thick and low viscosity fluids as being thin. All leading brands have one for service level sl, available in several viscosities. Engines run longer between topoffs, providing peace of mind they wont fail.
Dmitri kopeliovich low viscosity oils produce less friction and therefore decrease the fuel consumption and combustion gas emissions. Viscosity has a very important role it effects the heat generation in engine, bearing, brakes and gears,it governs the sealing effect and oil consuption and determines the ease with which the engine can start with varying temperature specially in. Us20050221998a1 low viscosity, high abrasion resistance. When comparing engine oils for your ride, the most important thing to keep in mind is the oils viscosity rating. Look for the viscosity grades recommended by the original equipment manufacturer oem, which you can locate in your owners manual. Gm dexos information center federal trade commission. Kinematic viscosities of common liquids like motor oil, diesel fuel, peanut oil and many more. The quality of an engine oil depends on the base stock and its properties as well as on the additives. The present invention provides an engine oil composition containing polymethylacrylate, zinc alkyldithiophosphate, molybdenum dithiocarbamate, a hindered phenol antioxidant, and a fixed mineral oil. Their initial specification defined five different numbered grades for motor oil 10, 20, 30, 40, and 50.
So, what does this all mean to protecting your engine. This oil is a tremendous improvement over the previous specifications. Its heatresistant synthetic base oils provide low volatility, excellent viscosity stability and strong oxidation resistance. Oil viscosity for older engine maintenancerepairs car. Pdf temperature relations of selected engine oils dynamic.
Motor oil is used for lubrication of internal combustion engines. All of the viscosity measurements presented are within 0. Viscosity is resistance to shear or flow in a fluid and a measure of the adhesivecohesive or frictional property. The properties of mixtures of the same oils with diesel fuel showed smaller changes than mixtures with gasoline. Sae published the first version of their standard sae j300 for motor oil viscosity. Engine oil viscosity classification sae international. Production of diesel fuel from used engine oil is involving chemical filtrations. Various types of engine oil on the market are created for various purposes. Motor oil viscosity is generally known as a measurement of thickness. Le white paper pung the simple back into viscosity 4 2019 lubrication engineers, inc. So while your engine requires the viscosity of a 30 grade oil when its at operating temperature, that oil also has the viscosity of a 5 grade oil when it is cold. Dynamic viscosity, also absolute viscosity, the more usual one typical units pas, poise, p. The current engine oil specification, api ck4, was released into the.
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