Faceoff: the Detroit DD15 vs the Cummins ISX Reviewed

Battle For Supremacy

Are you buying a new semi truck or replacing the engine in your current one? If so, you're probably weighing the differences between the Detroit DD15 and the Cummins ISX. The right engine is crucial for efficiency and performance, and selecting the right one can save you time and money down the road.

The first step is to consider what kinds of loads you're hauling and the primary type of terrain you travel. Driving lumber over the mountains or transporting liquid across flat plains benefit from different features.

Here are some comparisons between the Detroit DD15 and the Cummins ISX, including feedback from truckers who have actually operated each.

• The DD15 is more fuel-efficient than the ISX, particularly at RPM lower than 1,500
• The ISX has a wider power band than the DD15. meaning a larger range of efficient operating speeds
• If you transport heavy loads over mountain roads, the ISX has more horsepower and better pulling power
• Some truckers have encountered chronic fuel line problems with Cummins that don't tend to occur in the DD15
• If you're buying a new truck and have a preference of model, the DD15 is available only in Freightliners
• The DD15 has a proprietary asymmetric turbocharger that is designed for optimum performance with the Exhaust Gas Recirculation (EGR) system, resulting in fewer problems than the ISX as reported by truckers

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