Deere and Cummins Warn Tier 4 Owners as Texas High-Sulfur Diesel Waiver Runs to Nov. 13

John Deere Power Systems has issued an advisory to equipment operators — particularly those running Tier 4 engines — after the U.S. Environmental Protection Agency renewed a waiver on ultra-low-sulfur diesel requirements in Texas.

The EPA renewed the waiver on October 20, extending it until November 13 in response to a request from Gov. Greg Abbott to ease ongoing fuel supply disruptions in the state. The waiver allows the distribution of diesel with higher sulfur content, which Deere says could damage Tier 4 Interim and Tier 4 Final engines. Those engines require sulfur content of no more than 15 parts per million.

"Operating Final Tier 4 or Interim Tier 4 engines on fuel exceeding the recommended 15 ppm limit presents operational risks," the company says. "While higher sulfur levels will not necessarily cause immediate component failure, sustained exposure to non-compliant fuel can lead to system degradation and shorten the operational lifespan of aftertreatment systems, including Selective Catalytic Reduction systems requiring Diesel Exhaust Fluid and Diesel Particulate Filters."

Using higher-sulfur diesel that does not meet the standard specified in the equipment owner's manual could also affect warranty coverage for engine components, Deere says. Older, lower-tier engines — Tiers 1 through 3 and legacy engines — can tolerate higher-sulfur diesel, up to 500 ppm in some cases, and the company recommends reviewing owner's manuals to ensure the proper fuel is used.

Cummins has issued the same warning. "Cummins is aware of the temporary EPA waiver and continues to recommend that customers follow the fuel specifications outlined for their engines and equipment," the company said in a statement to Equipment World. "Failure to use the approved fuel (maximum 15 ppm sulfur diesel fuel for Tier 4 and 2007 and newer engines) can damage the engine and aftertreatment system."

For owners and for buyers of used machines, aftertreatment condition is increasingly a valuation issue: DPF and SCR components are among the costliest items to replace, and fuel and service records are becoming part of how a machine is priced.

Source: Equipment World

Cover image: Diesel particulate filter by Hatsukari715, public domain, via Wikimedia Commons.