Search Results

Certain diesel fuel specification properties are considered to be environmental parameters according to the European Fuels Quality Directive (FQD, 2009/EC/30) and previous regulations. These limits included in the EN 590 specification were derived from the European Programme on Emissions, Fuels and Engine Technologies (EPEFE) which was carried out in the 1990’s on diesel vehicles meeting Euro 2 emissions standards. These limits could potentially constrain FAME blending levels higher than 7% v/v. In addition, no significant work has been conducted since to investigate whether relaxing these limits would give rise to performance or emissions debits or fuel consumption benefits in more modern vehicles. The objective of this test programme was to evaluate the impact of specific diesel properties on emissions and fuel consumption in Euro 4, Euro 5 and Euro 6 light-duty diesel vehicle technologies.

It is widely known that different factors, such as cold properties of a fuel as well as a vehicle design, affect the cold operability limit of vehicles. In this study, the aim was to get a better understanding of the properties of modern Light Duty Diesel (LDD) vehicles (2014-2020) that define their cold operability temperature limit. Moreover, the aim was to find out what a responsible fuel producer can do, in addition to providing a proper fuel that meets the specification, to ensure that a vehicle stays operable at cold temperatures. Similar study was done 10 years ago by Neste with the LDD vehicles of that time [1]. Therefore there was a need to update the info to concern the modern LDD vehicles. In this study the operability limit difference between the worst and the best operating LDD vehicle was >10°C (nbr of LDD vehicles = 5) with the same fuel. The limits were determined in a cold chamber using a chassis dynamometer.

The sulphur level of diesel fuels began to be limited in Europe at the end the 20th century. Quite soon after that it was noticed that the processes for removing sulphur also removed other polar compounds and the natural lubricity of the diesel fuel was lost. Lubricity additives were introduced to restore lubricity properties. Also, a rapid laboratory method was developed to measure lubricity i.e. High Frequency Reciprocating Rig (HFRR). The method (HFRR) ISO 12156-1 was introduced in 1997 and included in EN 590. In recent years purely paraffinic diesel fuels, such as GTL (Gas To Liquid) and renewable HVO (Hydrotreated Vegetable Oil), have been introduced to the market. Unlike traditional biodiesel (FAME, Fatty Acid Methyl Ester), paraffinic diesel fuels require the use of lubricity additives to reach a sufficiently high level of lubricity.