The Cummins engine, a staple in RAM heavy-duty trucks, is undergoing several updates for 2025, sparking discussion among industry experts. A recent video by Truk Stuf, featuring JB Reviews, provided insights into these changes, focusing on key technical aspects.

One area of discussion surrounds the engine block. The video addressed rumors of a forthcoming new engine. He also added that this engine is still in the research and development phase. This extended development aims to prevent issues seen in prior engine releases.

Truk Stuf and JB Reviews talks about some updates regarding the Cummins 2025

A major point of contention is the use of compacted graphite iron, or CGI, blocks. He expressed a strong preference for traditional cast iron. Truk Stuf suggested CGI blocks are a cost-saving measure that sacrifices strength.

He explained these blocks are more susceptible to damage. As Truk Stuf stated, “I will never say that CGI is a stronger more viable option than old cast iron.” He further elaborated on his experience with these blocks, noting, “…why would you try to do weight savings where it’s critical at on the block…”

Another important update involves the intake manifold. He viewed this redesign favorably. He suggested Cummins appears to be taking cues from the aftermarket performance industry. These aftermarket parts often improve engine airflow.

Truk Stuff believes that this change will have a positive impact. This adjustment could also improve overall engine efficiency. He commented that Cummins engineers finally recognized that previous designs were creating “restriction” and that they needed to improve the engine’s ability “to breathe.”

6.5 inch blown hole within an engine block

The video also touched on engine starting systems. The discussion centered on the choice between grid heaters and glow plugs. However, the technician voiced concerns about the potential use of glow plugs. Specifically, he cited several disadvantages.

These include increased noise and a higher likelihood of part failure. As he put it, “More parts, more ability for parts to fail.” Furthermore, he also mentioned the design complexity associated with glow plugs. Therefore, he prefers the current grid heater system for its simplicity and reliability.

Finally, the transmission received attention (normally the Achilles heal of RAM trucks). The technician showed enthusiasm for the anticipated use of ZF 8-speed transmissions. He praised these transmissions for their robust design. He also noted their ability to handle significant power and torque.

From the perspective of a master technician, these updates present both opportunities and concerns. While some changes are viewed positively, others raise questions about long-term reliability. Time will tell if the 2025 Cummins can address these concerns in the final production models.