The sophisticated technology monitors the four core engine systems: fuel, air, electronics and after treatment

• The Air Management System uses turbochargers to force cool, clean air into the combustion chamber.  Electronics control the volume required at various loads and speeds.  Cross-flow heads and, where appropriate, four valves per cylinder dramatically improve air control to improve engine response, and increase fuel economy and performance.
• The HEUI Fuel System ensures that small, multiple shots of fuel are injected into the combustion chamber at the appropriate time.  Rate shaping - the control of fuel delivered during ignition delay and main injection - is made possible by the HEUI’s ability to operate independent of engine speed.  Engine performance is optimised by varying the idle and light load rate characteristics independent of rated and high load conditions.
• The CAT® Electronics ADEM 4 Electronic Control Module is fully integrated to achieve reduced emissions whilst maintaining excellent fuel economy, power and performance.
• The engine has been specifically designed to adopt additional technology to satisfy future requirements, such as a diesel oxidation catalyst mounted in the exhaust system.

The 350 hp (260 kW) MT835B, the 400 hp (298 kW) MT845B and the 460 hp (342 kW) MT855B tractors are powered by new CAT® C15 ACERTTM 15.2 litre engines. The two largest models, the MT865B and the new MT875B are powered by the new “clean” CAT® C18 ACERTTM 18.1 litre engines, the largest displacement engines on the market, providing rated power at 510 hp (380 kW) and an industry leading 570 hp (424 kW) respectively.

These new engines supply maximum performance and efficiency in all Challenger B series tracked tractors, with awesome pulling power to pull up to 3 scraper boxes through the toughest areas.