Stop-start technology – What is the long term effect on engines?

The technology from our award winning motorsport gear oils has now been transferred to gearbox oil for passenger cars, EE Transmission 75w90 for more information.

  • Less energy is lost within the gearbox, making the drivetrain more fuel efficient
  • Wear on components is reduced, making the drivetrain components last longer and improving reliability

Stop-start technology has become increasingly common in cars today. This is a system where, when your car is stationary for more than a short time, the engine is turned off automatically. If it’s manual the engine will start up as soon as you depress the clutch where as on an automatic it restarts as you depress the accelerator. It’s a simple idea – you avoid wasting fuel and reduce emissions by turning the engine off when it’s not needed. Drivers can find stop-start technology confusing or irritating - to the extent that some actually choose to turn it off.

Stop-start technology is very clever and it includes a more powerful, faster acting and more robust starter motor. However there is one factor that cannot be avoided – a higher number of stop-start cycles leads to more engine wear unless other changes are made. A normal car will be expected to go through 50,000 stop-start cycles in a lifetime whereas a stop-start car will exceed 500,000!

Obviously this big increase presents a significant increase in wear on an engine’s bearings.

Each time the engine restarts there is a short period of metal to metal contact when most wear takes place. At this point there is only a very thin layer of oil called ‘boundary lubrication’.

To minimise wear you need lower friction and a higher performing oil. Millers Oils have developed the Nanodrive range of oils to do precisely this.

Martyn Mann, Technical Director says “We’ve reduced friction with our oils and improved the durability of the oil film and believe that has to be the way forward with stop-start systems.”
 “We put a formulation together, tested it on a friction rig and found we could reduce the sliding friction between typical components like pistons and liners by 50 percent,” says Mann. With the development of this new lubrication technology any problems caused by extra stop-start wear should be avoided.

The same technology also offers benefits in hybrid cars. Hybrid cars are regularly switching from an electric to a petrol engine – for instance at higher speeds the electric engine stops and the petrol engine starts. This means exactly the same stop-start lubrication challenge needs to be addressed.

The Nanodrive technology was initially only available in Millers Oils racing engine oils range but is now available for everyday car use in their Energy Efficient Nanodrive range.

Martyn Mann