Oils, lubes & additives 36 www.aftermarketonline.net MAY 2026 Lower viscosity – greater challenge Chris Clarkson, Global Technical & Procurement Officer at Duckhams, explains the challenges that lower viscosity oils pose for oil formulators and outlines why choosing the correct oil is vital to ensure adequate vehicle protection. Lower viscosity oils offer fuel economy benefits. They have been developed to meet legislative requirements and OEM enhancements aimed at improving vehicle efficiency. Indirectly, they also offer emissions benefits. It’s simple mechanics – the thinner the oil is, the less drag there is. Less fuel is required to propel the vehicle, and fewer emissions are produced during fuel manufacturing. Lower viscosity oils are particularly common in hybrid vehicles, which account for an increasing share of the vehicle parc. A lower viscosity oil will pump more quickly on startup, as there is less resistance to flow. This is valuable in hybrids, where combustion engines more frequently start and stop as vehicles switch between battery and engine power. However, lower viscosity oils require highly complex chemistry. Reducing viscosity requires formulating an oil with enhanced technology/additives and base oils to ensure engines are properly protected. Even though oils like 0W20 and even 0W8 are thinner, they are more difficult and more expensive to make. Thinner does not equal cheaper. In fact, it’s quite the opposite. Lower viscosity means higher cost for oil manufacturers – and therefore mechanics and motorists. Manufacturers must blend oils that deliver all the protection engines need through a thinner film barrier. Volatility is a key concern, as the thinner an oil is, the more volatile it is. That means the potential for higher consumption in high-temperature applications, which is why higherperformance base oils are required to combat this increased volatility. These more expensive raw materials and increased research requirements drive up the cost of lower viscosity oils. Without these higher-value base stocks, oil would be consumed faster, and drivers would have to top up their oil more frequently. Low viscosity oils are becoming more common, but they are not right for every vehicle. With the ageing vehicle parc and millions of vehicles over 10 years old on our roads, they won’t suit most vehicles coming through workshops for some time yet. Workshops need to carry a variety of viscosity grades to meet demand. Mechanics must follow OEM recommendations. The latest, most sophisticated lower viscosity oils might be tempting as an upsell, but they could actually damage customers’ vehicles if misapplied. Using a thinner oil than recommended risks increased wear and damage to engine parts, the last thing any motorist or mechanic wants. When an engine heats up, the oil heats up and becomes thinner, so when an OEM recommends a product for their vehicle, it takes that into account. Using an oil which is too thin risks damage when it heats up to operational temperature and no longer provides the protection the engine needs. Technicians should be particularly careful with classic vehicles, as low viscosity oil can increase the risk of leaks, and modern base oils may not be compatible with seals used in older vehicles. If in doubt, always refer to the vehicle handbook and OEM recommendation to ensure you use the correct oil. Registration lookup tools like Duckhams Find My Oil can also help to identify the correct product and provide vehicle protection you can rely on. duckhams.com/find-my-oil
RkJQdWJsaXNoZXIy MjQ0NzM=