www.truckandtrack.com Autumn 2023 Truck and Track 43 OILS & LUBRICANTS Adrian Hill, Technology Manager at Morris Lubricants Diesel Particulate Filters (DPFs) are installed in the exhaust system to catch particulate matter (soot) and to prevent it from entering the atmosphere where it can cause health and environmental issues. Sensors monitor the working pressure across the unit and when it drops to a defined value, a regeneration cycle is initiated. This usually involves unburnt fuel entering the unit, causing a temperature spike that oxidises the soot (solid) to carbon dioxide (gas). Carbon dioxide flows out and the unit is good to go again. As mentioned previously, a small amount of oil is burnt during this process, and this creates a metallic ash that is swept into the DPF. However, the metallic ash that is generated remains behind and eventually the DPF will be unable to reach normal pressure ranges. Again, the vehicle will click into reduced power mode. Using the correct engine oil with the correct formulation will protect the engine components, and also help to ensure that the DPF has the best possible service life. When the DPF is working at its optimum levels then particulate emissions are controlled more effectively. To reduce emissions even further, efforts have been focused on improvements in fuel efficiency. New engine hardware architectures, designs and technologies are emerging that embrace multiple innovations. There’s no doubt that engine downsizing, in terms of the number of cylinders employed, will continue. 8-cylinder engines, with the odd exception (such as Scania), have already been moved down to 6 cylinders in numerous cases and with the adoption of variable geometry turbochargers, to give tailored boost depending on demand, power outputs have been maintained. Variable valve timing helps to ensure maximum fuel efficiency under a wide range of loads and operating conditions. Different construction materials are starting to come into play. For example, steel pistons are being used to cope with higher peak cylinder pressures and allowing the top compression ring to be moved closer to the crown, reducing the crevice volume where burn inefficiencies can occur. On top of these modifications, the aftertreatment devices are continuing to improve in design and effectiveness. Two stage AdBlue injection aims to improve NOx conversion, relying on a tailored engine oil formulation to ensure catalyst longevity. DPFs are removing even smaller particles and will remain effective longer by using the correct type of low ash engine oil. Another strategy to reduce emissions is to improve fuel efficiency. If less fuel is used, then emissions are also reduced. Improvements in fuel efficiency can be made by using engine oils that produce thinner oil films in the bearings and where the compression ring travels along the cylinder liner area. These thinner oil films result in less drag and therefore offer more useable energy that can be used by the wheels. To ensure that component integrity is not compromised, these thinner engine oil films are fortified with polymer chemistry to ensure there is no metal-to-metal contact. Polymers are essential when formulating 5W-30, 5W-20 and 0W-20 engine oils for the commercial vehicle sector. The modern heavy duty diesel engine is complex and is still evolving. These new architectures, technologies and fuelling strategies produce real world emission reductions, but they will only achieve this if they are fitted with new generation engine oils, which are as critical as any other component. Therefore, the choice of the correct lubricant can be complicated and a little confusing. The Versimax range of heavy-duty diesel engine oils from Morris Lubricants, have been formulated to work with the various aftertreatment devices, as well as reduce downtime, improve fuel efficiency and, of course, contribute to the reduction in engine emissions. This range of engine oils is used by fleet operators, maintenance technicians, mechanics and drivers to help rationalise usage where mixed fleets of vehicles and engine technologies are in operation. Engine oil choice should not be taken lightly, and the original equipment manufacturer’s guide should always be followed. The mixing of different types of oil must always be approached with caution, as using an inferior oil could cause damage or premature failure. As always, seek professional advice if there is any doubt. If you are unsure which oil will suit your needs, call the Morris Lubricants Technical Helpline on 01743 237541 or visit morrislubricants.co.uk.