I read the technical article Black Magic? in the July 2015 issue with interest and I have a question about low-sulphur diesel. I started using Sasol 10 ppm sulphur diesel in my 2007 Isuzu KB250 diesel bakkie as well as in my old 135 Massey Ferguson tractor. Both use mechanical injector pumps that rely on the diesel to lubricate it. Will 10 ppm diesel suffice or should I rather start using 50 ppm diesel again? I am concerned about the high sulphur content of 50 ppm diesel, but also worried that the lubrication properties of lower sulphur diesel are not sufficient to protect the vehicles’ injector pumps.
Answer: It’s a misperception that lower-sulphur diesel’s lubricity qualities are worse than those of higher-sulphur diesel (as stated in the aforementioned technical article). In fact, it is quite the opposite as oil companies include their most advanced additive packages in the lower-sulphur diesel. It is therefore an overall superior product: not only regarding sulphur content, but lubricity. It would be beneficial (for lubrication) to use low-sulphur diesel
in any engine, regardless of its age.