Thicker VS thinner motor oils – which ones are better suited for your car? To understand this fully, our readers should first understand the grading and specification for motor oils, a comprehensive guide on which has been provided in one of the earlier articles in this series.
In a nutshell, however, the lower first digit in a motor oil specification means that the oil flows better even at lower temperatures, allowing for better engine protection and easy cranking during cold starts. The higher value in the grade, on the right side denotes the performance of the engine at higher temperatures.
To understand, why it’s more recommendable to use motor oils with 5W30 or 10W30 grade over their 20W50 counterparts, we have to first realize that the construction of modern engines is very different from their predecessors. Modern engines are made almost to perfection, with very low tolerance and with a very high degree of precision. Unlike engine from previous generations, which suffered from relatively uneven grinding surfaces and had leakage issues over time owing to engineering limitations, modern engines are built with almost atomic precision.
This development in engine technology has allowed auto makers to recommend engine oils which flow better and allow for better cold starts and provide protection from the very first stroke of the piston. Also, motor oils which flow better allow for much less resistance as compared to their thicker counterparts, thus enhancing fuel efficiency and refinement significantly.
Since almost every modern engine on today’s cars is liquid cooled, it runs at about 180-190 degrees (F) or 80-95 degree Celsius at all times. The design and construction of these engines insulates them to a very large extent from the outside temperature. And since modern engines are also built to much smaller mechanical tolerances they are designed to use the lighter weight, more flowy engine oils. Using thicker engine oil, like a 20W-50 specification would make the oil pump work very hard to get the lube flowing. This not only loads the fuel pump up, but also makes it difficult for the mechanical parts to move.
Now, the safest way to go about choosing the right grade and specification for your car is to go with the manufacturer’s recommendation. And you’d observe that almost all the major carmakers these days are recommending lighter, thinner, easy-flowing engine oils. For example, Hyundai Motor India recommends a SAE 5W30 specification for all its new petrol cars in India. As another example, Maruti Suzuki, on its official driving tips page suggests that using heavier engine oil than recommended can lead to a decrease of in fuel efficiency to the tune of 2 percent or more.
To cut a long story short, easier start-up, better engine protection, wider operating temperature range and enhanced fuel efficiency are some of the reasons why most manufacturers are opting for 5w30 or 10w30 oils over 20w50 oils for their modern cars. The latter oils are suitable for older engines which are prone to leakages.
In this context, our series sponsors Motul, who are recognised as the makers of some of the finest motor lubes worldwide, offer a couple of products which are very suitable for your everyday cars.
The first of these is the 4000 Motion Plus 10W30 lube, which is a very competitively priced mineral oil and recommended for cars running all varieties of fuel including petrol, diesel, CNG and LPG. This oil is engineered to offer excellent anti-sludge and anti-deposit properties for a longer engine life. The low viscosity grade allows for rapid flow of oil on cold starts while the low friction allows for enhanced fuel efficiency.
Motul also offers the 4100 Power 5W30 as a semi-synthetic (Technosynthese) option for those looking for an even more premium engine oil for their modern cars. The oil can be used on cars meant to meet BS III or BS IV norms and running a variety of fuels including Petrol, diesel, CNG or LPG. The 4100 Power offers excellent fuel economy along with enhanced protection to engine parts at higher temperatures. Along with providing easy cold starts and complete lubrication during cranking and warm-up, this oil also prevents sludge formation. As a great additional feature, the 4100 Power also actively prevents degrading of emissions controls systems such as catalytic converters.
We hope this article added to your knowledge of lubes. If you have any questions or doubts about the most suitable engine oil for your car, do give us a shoutout on any of our social channels. We will have the lube experts at Motul answer your queries in detail.