Myth Buster: Tier 4 Final Doesn't Always Equal Urea

Think all U.S. EPA Tier 4 Final engines for well service applications require Diesel Exhaust Fluid (DEF) — otherwise known as urea? You’re not alone. It’s a common misconception across the industry. But in reality, if you need a high-power model, you have another option. All Cat® Tier 4 Final engines above 750hp are urea-free. That includes C18 models often used to power blenders and coil tubers, as well as C27, C32 and 3512E engines.

Instead of featuring a Selective Catalytic Reduction (SCR) system that requires DEF, our Tier 4 Final engines rated above 750hp use Exhaust Gas Recirculation (EGR) and a Diesel Oxidation Catalyst (DOC) to reduce emissions instead. (The DOC also provides added sound attenuation for a quieter jobsite.) It’s a passive aftertreatment technology that’s practically invisible to your operators — much like what you’ll find on your car. We chose that solution strategically for these reasons:

• No de-rate or shutdown: If you run into a problem with an SCR system or run out of DEF, your engine will de-rate or shut down to comply with EPA regulations — and that can stop you from operating. That’s a risk you don’t run with Cat Tier 4 Final engines above 750hp.
• Greater simplicity: On a busy frac site, it can be easy to mix up diesel and DEF. Eliminating the need for DEF reduces the risk of costly mistakes and makes troubleshooting simpler, too. You also don’t need to worry about where to store it, how to prevent contamination or how to keep it from degrading or freezing at extreme temperatures. For added simplicity, the EGR system and DOC are installed on-engine at the factory versus DEF tanks that are packaged off-engine.
• No added costs or downtime: With our Tier 4 Final engines above 750hp, there’s no need to pay for DEF, additional consumables like urea filters or the labor required to truck in and handle the fluid — and no need to stop to fill DEF tanks between pumping stages. Plus, the DOC is zero maintenance, and the EGR system only requires some component replacement at overhaul.

Want to know more about our urea-free Tier 4 Final engines above 750hp? Your local Cat dealer can walk you through all the models available and their ideal applications.