Passenger car motor oil additives

Friction modifiers for passenger car motor oil

Our Perfad™ range of organic friction modifiers (OFMs) have been tested using a wide range of commercial engine oils available in Europe, the United States of America, Japan and other regions of the world.

In one demonstration of our Perfad range, we used the Mini Traction Machine (MTM) to evaluate the performance of a European oil (5W-30) that was top treated with our Perfad OFMs. It is important that surface-active additives are compared after thermal and mechanical activation, so the Stribeck curve below (Figure 1) shows both initial friction coefficient and then the friction of coefficient after 120 minutes of surface conditioning. 

Our reference OFM (Glycerol mono-oleate, GMO) provides a reduction in friction compared to EU Oil 1 of approximately 8% at a speed of 0.005 m/s, whilst our Perfad series demonstrates improved friction reduction. Perfad 3000 provides a 13% reduction, Perfad 3006 provides a 40% reduction and Perfad 3050 a 90% reduction. 

In this particular engine oil and under these conditions, Perfad 3050 has effectively eliminated the boundary regime through the formation of a very low friction film. This suggests that polymeric friction modifiers (PFMs) have the ability to operate under higher load conditions while still maintaining low friction.

Figure 1: Stribeck curve showing initial coefficient of friction and after 120 minutes of run-time. 

Whilst the above example demonstrates OFM performance in 5W-30 oil, the industry has moved towards lower viscosity oils. 0W-20 grades and below are now common globally in passenger cars. Friction modifiers for these lower viscosity oils must still provide protection against wear, must be compatible with other formulation components and must also provide fuel economy benefits.

Base oil selection for passenger car engine oils 

Figure 2: OEM vehicle production forecast to 2030, IHS Markit Alternative Powertrain production Forecasts, December 2019

REWITEC™ PowerShot™ surface repair additives in engine oils 

Our inorganic silicon-based additive technology can help improve fuel economy and reduce wear in passenger cars. This was demonstrated using a commercially available low-viscosity European oil using a pin-on-disk tribometer. 

Upon additive addition, relative friction can be reduced and sustained when entering stable interface conditions. PowerShot can be used in first-fill engine oils to protect from first use, or as a top-treat aftermarket additive to help repair and increase the efficiency of older engines. 

Figure 3: Pin-on-disc tribometer measurements demonstrating a reduction in friction upon addition of PowerShot additive.