## 1 Introduction  
Since scientists have become aware of how harmful and irreparable carbon footprints can be, as well as the fact that about half of the lubricating oil used in an engine is released into the environment through engine exhaust vapors, leaks, and spills, many researchers have started to make use of technological advances such as renewable resources, biofuels, and synthetic oils obtained from vegetable sources to reduce the damage of carbon footprints. This is important because previous investigations into fossil substitution with vegetable oils show that they are more than 95% biodegradable, eco-friendly, less toxic, and have a low volatile effect on the environment [1, 2]. Economically, edible and non-edible vegetable oils can be easily produced by local farmers, making them an important economic driver. In contrast to what has previously been stated, the extraction of fossil oils is costly, and the oils take a long time to obtain [3, 4]. Since lubricants work as an antifriction interface in an engine, with viscosity being their main characteristic, the parameters to be considered when selecting a lubricant should include its chemical stability, corrosivity, environmental effects, and availability, as well as its thermal behavior. Thus, it is necessary to take an engine's thermal behavior into consideration. Furthermore, it is important to keep in mind that an oil's thermal diffusivity must be related to its heat penetration, while thermal effusivity must be related to its superficial heat interchange. It is important to note that friction will produce interfacial heat, making its dissipation necessary; therefore, thermal effusivity is a crucial thermal parameter to take into consideration [5]. Due to the fact that vegetable oils have been used in lubrication applications [2], as well as cutting fluids [4] and biofuels [6], they have been tested for their ability to modify viscosity and thermal properties when used as additives for fossil oils [7; 8; 9]. Modifications to various vegetable oils' thermal properties have been reported as a function of temperature [10; 11] when adding nanoparticles [12], as biofuel bases [13], and when modifying tribological and thermal properties [7; 14; 15]. Hence, the influence of a vegetable oil as an additive in a lubricant oil has been reported to be successful. Additionally, lower emissions of NOx (25-62%) and SOx (61-88%) have been reported after adding colza oils [16]. Since tocopherol, a lipid-soluble substance, has the capability to reduce free radicals and has antioxidant properties, it has become an important subject of investigation [3; 17]. Samples have been chosen considering the fatty acid composition and the high tocopherol content which can be found in rapeseed, sunflower, and almond oils, at 18-51, 1-59, and 1-44 mg per 100 g, respectively [17; 18]. As is well known, the sunflower (_Helianthus annuus_) seed is used as a raw material for oil extraction. In order to do so, the oil is extracted by pressing the seeds or by leaching using solvents [19]. Since the primary use of sunflower oil is as edible oil, it is one of the four most important oils in the world. Furthermore, this oil is made up of polyunsaturated fatty acids, among which linoleic, linolenic, and oleic compounds stand out and are an abundant source of tocopherol [20]. Furthermore, sunflower oil has gained attention because of its capacity to be used as biodiesel through transesterification [21]. An almond (_Prunus dulcis_) is a shelled seed found in a tree, and its oil is a widely used product for everyday use. However, only when the almond oil is submitted to transesterification can it be used for biodiesel [22]. The best-known method to extract its oil is by dry-pressing it. Additionally, rapeseed (_Brassica napus_) is a bright yellow flowering plant. Its oil extraction is carried out by employing three different methods: cold pressing, hot pressing, and extraction with hexane.