Choosing between the Cummins L9 and ISX often comes down to your operational requirements—and displacement plays a big role in that decision.
The L9, with its 8.9L displacement, is well-suited for medium-duty trucks, buses, and municipal vehicles. Its smaller size means lower fuel consumption, reduced maintenance costs, and easier integration into lighter chassis designs. It’s a reliable workhorse for regional transport and vocational applications.
The ISX, with a 14.9L displacement, is built for serious heavy-duty work. It delivers higher torque output and sustained power for long-haul trucking, oversized loads, and off-road heavy equipment. However, this larger displacement comes with higher fuel usage and maintenance demands.
If cost efficiency and versatility are your priorities, the L9 will serve you well. If raw power and durability under extreme loads are essential, the ISX is the engine to trust.