Cat Tier 4 Technology


Caterpillar designed Tier 4 Interim products with Tier 4 Final standards in mind. By planning ahead, we were able to minimize design changes and deliver the reliability and performance you demand. Every Tier 4 Final engine is equipped with a combination of proven electronic, fuel, air and aftertreatment components, based on engine size, application and the geographic location in which it will work.

Applying proven technologies systematically and strategically lets us meet your high expectations for productivity, fuel efficiency, reliability and service life. The right technologies fine-tuned for the right applications results in:

IMPROVED FLUID EFFICIENCY Up to 5% improvement over Tier 4 Interim products (including Diesel Exhaust Fluid consumption).
HIGH PERFORMANCE across a variety of applications.
ENHANCED RELIABILITY through commonality and simplicity of design.
MAXIMIZED UPTIME AND REDUCED COST with world-class support from Cashman Equipment.
MINIMIZED IMPACT of Emission Systems: designed to be transparent to the operator without requiring interaction.
DURABLE designs with long life to overhaul.
DELIVERING better fuel economy with minimized maintenance costs while providing the same great
power and response.


The electronics used in Cat Tier 4 Final engines are more powerful and robust than ever. Increased features and connection commonality improve the customer experience and increase quality and reliability. The over-foam wiring harness adds to reliability even in the most demanding applications.


As a key component of Cat Tier 4 Technology, injection timing precisely controls the fuel-injection process through a series of carefully timed microbursts. This injection timing provides more control of combustion for the cleanest, most efficient fuel burn. To maximize
customer value, Caterpillar engineers specified fuel systems based on the power and performance demands for each engine.

High-Pressure Common Rail Fuel Systems with full electronic injection improve precision and control that boost performance and reduce soot for the C7.1 ACERT™ and C9.3 ACERT.

Advanced MEUI™-C injector platforms handle increased injection pressures and more precise fuel rates.

These durable injectors enhance responsiveness while controlling soot in the C13 ACERT, C15 ACERT, C18 ACERT, C27 ACERT and C32 ACERT.


Cat Tier 4 Final engines feature innovative air-management systems that optimize airflow and enhance power, efficiency and reliability. We apply a range of simple, reliable turbocharging solutions, based on engine size and application. This allows us to match turbo performance to rated output for high productivity, excellent fuel efficiency, long life and low operating costs.


The Cat NOx Reduction System (NRS) captures and cools a small quantity of exhaust gas, then routes it back into the combustion chamber where it drives down combustion temperatures and reduces NOx emissions. The result of more than a decade of Caterpillar engineering research into this technology, the NRS is designed to be the most reliable system of its type.

Cat Tier 4 Final Brochure