Whether it is through driver training, improving truck/trailer aerodynamics or optimising tyre pressures, commercial vehicle operators across the UK are continually looking at ways to improve the fuel economy of their vehicles to help offset rising costs at the pump.
While some of the above, much publicised, examples have helped commercial vehicle operators to significantly improve fuel consumption, where next for businesses in the daily drive to further reduce costs? One option is to switch to the latest fully synthetic, low viscosity, low friction engine oils.
Fuel economy benefits of low viscosity engine oils
Leading commercial vehicle lubricant suppliers such as ExxonMobil continue to invest in research and development and work in close collaboration with the world’s leading Original Equipment Manufacturers (OEMs) to develop engine oils which help to optimise engine performance whilst also delivering benefits such as improved fuel economy.
Today, fully synthetic SAE 5W-30 grade lubricants are available which can have a positive impact on fuel economy, allowing operators to use lower viscosity oils without sacrificing performance. Using a low “W” grade, for example a 5W-XX over a 15W-XX heavy-duty diesel engine oil, would provide a higher chance of capturing potential fuel savings. In addition, a multigrade lubricant with a lower high temperature viscosity grade, for example a XW-30 compared to a XW-40 heavy-duty diesel engine oil, could also provide improved savings. These two modes of fuel savings, combined in a 5W-30 grade, offer the greatest chance of harnessing possible fuel savings. For low temperature and stop-and-go operation there is the potential for up to 5% fuel savings1. For normal operation, once the engine is warmed up, there is the potential for up to 2% fuel savings.
Selecting the optimum viscosity at the outset is important, but it is only through using fully synthetic engine oils that this viscosity can be maintained, with the synthetic technology helping to minimise lubricant break-down and thickening. If an oil can maintain its original viscosity, there is potential for fuel savings of up to 5 percent over the course of an oil drain interval. Viscosity retention has a significant influence on total fuel savings because it plays a role across all operating conditions.
No compromise on protection
However, it is vital that this move to lower viscosity heavy-duty engine oils does not compromise engine protection, particularly given that - due to the prevailing economic climate - commercial vehicle operators are looking to run their vehicles for longer whilst minimising maintenance costs. This is why the selection of fully synthetic oils is crucial.
Previous-generation, mineral-based engine oils, cannot offer the same amount of protection as their synthetic equivalents, as well as enabling emission technologies to function effectively.
Alongside OEM recommendations and approvals, operators would do well to ensure that their low viscosity, low friction engine oil offers:
- Enhanced engine protection the oil must demonstrate excellent cleanliness performance across a range of engine technologies, as well as having a class leading Total Base Number (TBN) and TBN retention for a low ash product, to help engines run longer
- Excellent low temperature performance - effective lubrication at low temperature helps combat wear under cold-start conditions
- Excellent thermal and oxidation stability - soot particles, contaminants, and by-products of oil break-down can lead to oil thickening which can increase fuel consumption and wear. A lubricant must be specifically designed to resist thermal, oxidative and soot induced thickening
- Extended oil drain intervals a lubricant which demonstrates excellent bore polish and wear control, accompanied by low volatility, helps keep trucks on the road for longer
- Emission system protection - low ash oils such are required to allow Diesel Particulate Filters (DPF) to function properly
Advanced engine oils available on the market
One oil that meets all of the above requirements is Mobil Delvac 1 LE 5W-30 - formulated to achieve optimised performance as demonstrated by its SAE 5W-30 viscosity grade designation and extended drain approvals. It is a fully synthetic high performance, low friction, heavy-duty diesel engine oil that helps extend both engine and emission system life while providing long drain capability and fuel economy potential for modern diesel engines, including those fitted with Diesel Particulate Filters (DPF).
Mobil Delvac 1 LE 5W-30 utilises state-of-the-art technology to deliver exceptional performance in modern low emission engines. Mobil Delvac 1 LE 5W-30 is recommended for use in a range of heavy-duty applications and operating environments.
It simultaneously meets MB-Approval 228.51 and MB-Approval 228.31 in a 5W-30 grade, ACEA E6/E7/E9, MAN M 3477, Volvo VDS3/VDS4 and other major OEM specifications.
Recently reformulated, Mobil Delvac 1 LE 5W-30, provides commercial vehicle operators with the potential to optimise engine performance and improve fuel economy in more trucks. The new Mobil Delvac 1 LE 5W-30 oil has more approvals than the previous formulation, and meets the requirements of the majority of Euro VI engines developed by leading Original Equipment Manufacturers (OEMs) such as Mercedes-Benz, Volvo, Cummins and MAN.
To meet Euro VI emission targets, all Euro VI engines will incorporate exhaust after-treatment technologies, involving a combination of Selective Catalytic Reduction (SCR), Exhaust Gas Recirculation (EGR) and Diesel Particulate Filter (DPF) systems. However, these after-treatment devices can be sensitive to lubricant components. With its low sulphated ash, phosphorous and sulphur (‘low SAPs’) formulation, the new Mobil Delvac 1 LE 5W-30 can deliver outstanding emission system protection for modern engines, including Euro VI.
The new formulation has also been proven to offer significant fuel economy benefits in commercial vehicles. Independent fuel economy tests were recently conducted at Millbrook, a leading international vehicle test and development facility in the UK. Two Volvo FM440 Euro V trucks, loaded to 75 percent Gross Vehicle Weight (circa 44,000kg) undertook a series of fuel economy tests under highway driving conditions. Mobil Delvac 1 LE 5W-30 achieved an average fuel economy gain of 1.8 percent.