The results of dynamic viscosity versus dilution rates are presented for small after-tribometer-testing samples of SAE 15W40 mineral oil diluted by four biodiesels (from canola, peanut, and soybean and chicken fat oil). This research presents new methods to test viscosity reductions because of biodiesel addition in mineral oil and to assess prediction of mixture viscosity considering the chemical breakdown of biodiesel. It is also possible that such oil-biodiesel mixtures undergo further viscosity decreases when subjected to the high temperatures and high contact pressures typical of internal combustion engine boundary lubrication. Dilution by biodiesels may substantially alter oil lubricity and lead to reduced viscosity, which produce tribological changes on engine materials. You may also wish to test the viscosity again after several hours in operation.The use of biodiesels in internal combustion engines leads to tribology concerns because significant oil dilution occurs when biodiesels leak into the oil pan. These would include calculating the right proportions in terms of volume instead of weight, mixing the oils properly to get a uniform mixture, and utilizing clean containers and a clean environment so as not to contaminate the lubricant with airborne particles or moisture.Īfter completing the mixture, measure the viscosity of the blend to ensure you have achieved your target. However, there are several concerns to keep in mind when blending different oil viscosities. For instance, if you mix an oil with a viscosity grade of 68 and an oil with a viscosity grade of 22, the proportions needed to attain a viscosity grade of 32 are 35 percent of the oil with a viscosity grade of 68 and 65 percent of the oil with a viscosity grade of 22.
You can find charts on the internet to help identify the correct blending proportions. In this case, it should be an oil with a viscosity grade lower than 32. If you have checked the equipment manufacturer recommendations and lowering the viscosity of the oil is an option, the best recommendation would be to use a lubricant of the same brand and product line with a lower viscosity. Mechanical problems leading to shorter equipment life can occur.
When lubricants are mixed with fuel or different lubricant types, this balance is often upset. Today's high-performance lubricants are formulated with a carefully selected balance of performance additives and base stocks to match the lubrication requirements of the equipment in which they are used. In addition, the flash point of fuel is very low compared to that of a lubricant, which could create a fire risk. Mixing fuel with oil is not recommended, as the fuel would not have the same formula as the lubricant. Not only is there a risk of incompatibility but also of losing the protective film the oil is providing at a viscosity grade of 68. When mixing oils, it is important to consider the desired viscosity as well as the lubricant's compatibility with the diluting product.
Always ensure that the viscosity of the oil in use meets the original equipment manufacturer's recommendations. The main function of a lubricating oil is to create and maintain a lubrication film between two moving metal surfaces, and this function is dependent on the oil's viscosity. When it comes to lubrication, an oil's viscosity is considered the most important parameter. Some have suggested mixing it with fuel." I know one way is to mix it with the same grade of oil from the same producer of a lower viscosity. "Could you suggest if and how I can reduce the viscosity of a mineral oil? For example, I have an oil with a viscosity grade of 68 and want to change it to a viscosity grade of 32.