Ultra Low Sulfur Diesel

Required For Engines Meeting Tier 4 Interim or Equivalent Emissions Regulations

Ultra-Low Sulfur Diesel (ULSD) fuel is legally required for Tier 4 Interim engines in North America and Stage IIIB in the European Union.  The ULSD in North America must contain 15 parts-per-million (ppm) or less sulfur content. In the European Union, ULSD must legally be 10-ppm at the point of manufacture and is expected to be 15-ppm at the point of use.

Availability of ULSD is very limited outside of North America and the European  Union – so it is critical to not operate an engine requiring ULSD in a country without available ULSD supply.  Using high sulfur content fuel will damage the engine and aftertreatment system.

Here are answers to some commonly asked questions regarding the use of ULSD fuel in Tier 4 Interim and Stage IIIB engines.

Could today’s off-highway fuel be used in Tier 4 Interim/Stage IIIB engines? Tier 4 Interim/Stage IIIB engines must use ULSD. It is not possible to comply with the legally required PM emissions standard with today’s off-highway fuel which has a higher sulfur content.

What happens if higher sulfur fuel is inadvertently used in Cummins Tier 4 Interim/Stage IIIB engines? A one time inadvertent tank of diesel fuel with greater than 15-ppm sulfur content will not damage the engine and aftertreatment system. The system will clean itself out when ULSD is re-introduced. However, continued improper fuel use of sulfur levels greater than 15-ppm with Cummins Tier 4 Interim engines can permanently damage the engine and aftertreatment systems within a short period of time. This damage could possibly cause the engine to be inoperable and cause unplanned downtime and expenses.

Can ULSD be used in Tier 3/Stage IIIA or other engines? Yes.  Current Tier 3/ Stage IIIA engines will work fine on ULSD.  It is backwards compatible. 

When will ULSD fuel be available? ULSD is available today. ULSD was widely introduced in North America in 2006 and more recently in the European Union for emission compliant on-highway engines. Both the EPA and EU already have ULSD in place with fuel producers and distributors before the 2011 regulations.

Can biodiesel fuel be used with Cummins Tier 4 Interim/Stage IIIB engines? Cummins Tier 4 Interim/Stage IIIB engines are compatible with Biodiesel blends up to B20 as long as the fuel does not exceed 15 ppm sulfur content.