Modern Low-Sulphur Fuels and Less Lubricity

One of the byproducts of using low-sulphur fuels is less lubrication in the engine and more engine wear.  Lubricity is the measure of the reduction in friction and or wear by a lubricant. The study of lubrication and wear mechanisms is called tribology.

Measurement of Lubricity

The lubricity of a substance is not a material property, and cannot be measured directly. Tests are performed to quantify a lubricant’s performance for a specific system. This is often done by determining how much wear is caused to a surface by a given wear-inducing object in a given amount of time. Other factors such as surface size, temperature, and pressure are also specified. For two fluids with the same viscosity, the one that results in a smaller wear scar is considered to have higher lubricity. For this reason lubricity is also termed a substance’s anti-wear property.

Million Mile High RPM Stress Test

Southwest Research conducted a one-million mile high RPM stress test with TK7 Products.  Two engines were tested – one with base fuel only – which failed the test – and one with base fuel and the TK7 fuel nanotechnology – which went to the end of the million miles at high RPM.

The temperature for the engine with base fuel and TK7 never exceeded normal operating range.  You can see the amber synthetic lubricant left behind when burning TK7 in an engine and the original honing of the cylinder sleeves.  This lubrication improves the life of the engine, the life of the emissions system, and helps to fill any scarring which improves compression as well.  The results of running TK7 is fewer repairs, more uptime, and lower operating costs

1-Million Mile High RPM Stress Test - Southwest Research Institute

Lubricity in Diesel Engines

In a modern diesel engine, the fuel is part of the engine lubrication process. Diesel fuel naturally contains compounds that provide lubricity, but because of regulations in many countries (such as the US and the EU), sulphur must be removed from the fuel before it can be sold. The hydrotreatment of diesel fuel to remove sulphur also removes the compounds that provide lubricity. Reformulated diesel fuel that does not have biodiesel added has a lower lubricity and requires lubricity improving additives to prevent excessive engine wear.[1] [2] [3]


  • Reformulated Diesel Fuels and Fuel Injection Equipment; Author: Hugh C. Grigg (Lucas Powertrain Systems) Presented at the New Fuels and Vehicles for Cleaner Air Conference, January 11-12, 1994, Phoenix, Arizona. (Retrieved via Google from a publication of the National Biodiesel Board, entitled Lubrication)
  • Fuels for Diesel Engines — Diesel Fuel Injection Equipment Manufacturers Common Position Statement, Signed by: Delphi Diesel Systems, Stanadyne Automotive Corp., Denso Corporation, and Robert Bosch GmbH, issued June, 2000 (Retrieved via Google from a publication of the National Biodiesel Board, entitled Lubrication)
  • Diesel Fuel Lubricity Authors: Paul Lacey and Steve Westbrook (Southwest Research Institute) SAE paper 950248, International Congress and Exposition, Detroit, Michigan, February 27-March 2, 1995 (Retrieved via Google from a publication of the National Biodiesel Board, entitled Lubrication)