Industry trade body, the Verification of Lubricant Specifications (VLS), has warned that workshops need to ensure the correct specification of oils are used in vehicles. There are potential risks with using newer engine oils in older models.
The number of vehicles is growing, but they are also aging. According to the latest data from the SMMT, there were around 35.7 million cars on UK roads by the end of 2023, with the average age at nine-years old. However, 47.8% of models are over 10 years of age, with 30.7% of the total over 12-years old, equating to around 10.9 million cars.
Just four years ago, in 2021, the average age was eight, demonstrating a substantial increase. The economic impact of COVID-19, automotive supply chain issues, uncertainty about electric vehicles and the future of the internal combustion engine, inflationary pressures and slow economic growth mean that motorists are holding onto their vehicles for longer than ever.
“On the one hand, this is good news for workshops,” Harald Oosting, Chairman of VLS comments. “With older vehicles on the roads, there is more demand for servicing, repairs and MOTs. However, as cars age, some aspects of servicing, such as choosing the right engine oil, can become more complex.”
Engine technology has evolved significantly. To meet government requirements for reduced emissions and consumer needs for economy and performance, smaller engines are running at higher temperatures to maximise efficiency, power output and fuel economy. Longer oil drain intervals, taken together with smaller sumps and the need to minimise emissions, have created the need for less viscous, synthetic or semi-synthetic oils to provide the lubrication required in these challenging conditions.
Suitable lubricants?
But are these highly efficient, sometimes ultra-low viscosity lubricants suitable for the ageing vehicles being serviced in workshops? The latest formulations are specifically developed for the most modern engines.
Traditionally, when newer oils were developed, some were designed to be ‘backwards compatible’. However, with an increasingly complex range of industry and OEM specifications, backwards compatibility cannot be assumed. Subtle yet important differences concerning viscosity characteristics and/or additive chemistries are reflected in specifications that must be acknowledged during regular servicing.
For example, a 2021 VW Polo 1.0 mpi requires an SAE 0W-20 engine oil complying with the latest VW 508.00 specification, part of which mandates very low high temperature, high shear properties (HTHS) to improve fuel efficiency. HTHS measures the viscosity or resistance to flow of an engine lubricant at elevated temperatures under constant shear.
This oil would be unsuitable for a 2017 VW Polo 1.0, which requires an SAE 5W-30 oil conforming to the older VW 504.00 specification, with higher and exclusively different HTHS properties. Use of a VW 508.00 compliant engine oil in place of VW 504.00 would potentially result in accelerated wear of engine components. In contrast, a VW 504.00 compliant engine oil instead of VW 508.00 would affect emissions and fuel economy.
OEM specifications themselves evolve, adding to the complexity. For example, VW 504.00/507.00 has kept the same specification reference, but some tests behind it have been updated, and the severity has changed.
Workshops rely on lubricant manufacturers conducting regular auditing and testing through comprehensive Quality Management Processes to ensure that products remain compliant, and mechanics are given the correct information to make their engine oil choice.
Potential damage
Generally speaking, using the wrong oil risks damage to emission control systems, accelerated wear in gears and bearings and the formation of piston deposits, leading to increased maintenance costs. Left unchecked, it could lead to eventual engine failure, meaning higher maintenance costs for your customers and potential damage to your business’ reputation.
If you put a low viscosity, low SAPS (Sulphated Ash, Phosphorous and Sulphur) oil in a vehicle requiring high levels of SAPS and viscosity, it may not offer the wear protection required. The additives for a lower SAPS oil will differ as well.
Additives help to provide the performance characteristics of an engine oil, but modern lubricants are designed to deliver performance through a thinner, less viscous oil that might not be suitable for older cars.
It could be tempting to use cheaper oils to offset rising costs. However, the cheapest possible oil could be a full SAPS oil intended for older vehicles or even contain untested additives. This could have a negative impact on the exhaust emission system, poison the catalyst or block the Diesel or Gasoline Particulate Filters, reduce the overall efficiency and result in failure of the particulate filter or catalyst, both expensive to replace.
Too much phosphorous from a high SAPS oil can also poison the Selective Catalyst Reduction units designed to control Nitrogen Oxide emissions. Short-term gain may lead to long-term pain for you and your customers.
Check the specs
For technicians selecting oils for the vehicles in their workshops, online lubricant databases operated by most lubricant companies provide a recommendation as a starting point for the correct oil based on a vehicle’s registration.
Technicians should verify this recommendation by direct reference to the vehicle manual and also the actual product claims in marketing literature, technical data sheets and product labelling provided by their supplier. Looking beyond the viscosity to specific performance claims such as the ACEA sequences and OEM standards should ensure that the lubricant is fit for purpose in that specific vehicle. Be careful with generic OEM claims such as ‘Suitable for Use’ without checking the necessary underpinning technical data that supports the claim.
If workshops are in any doubt about which oil to use for a particular vehicle, they should contact the vehicle manufacturer for assistance.
You can find out more about VLS and keep up to date with the latest case investigations at the VLS website: https://ukla-vls.org.uk/
If you have any concerns about a lubricant’s ability to deliver what it claims, you can report your concerns to VLS by calling 01442 01442 875922 or emailing admin@ukla-vls.org.uk.
