It may or may no be a trouble some design? But the fact is, the In-line design is to limiting, the engine compartment has to be way to long and high for it to be used in anything but a full size truck. Even the full size trucks are limited by the design, the V-8 and or V-6 configuration allows much more versatility. They allow for lower more sweeping hood lines, which makes for better aerodynamics and more modern design. There the I-6 cylinder Cummins is limited by height, length and weight, the Aluminum V configuration is not. The HP ratings are as high or higher then the ISB, along with similar torque rating.
As of right now, no manufacturer has signed on with Cummins to further develop and use these new engines, why?? not real sure. We know Ford has openly stated they want a V-6 diesel for the 150 series trucks and smaller SUV's. Chrysler has not expressed this concern, but has stated they will run a 4cyl diesel engine in the Liberty in early '05. Personally I think they would be completely insane not to actively pursue this new diesel technology and work to incorporate these engines into their existing line-up of trucks and SUV's. The debate over In-line Vs V-block design reminds me of the Jeepers and there "real jeeps have round headlights" campaign. The design of the round vs square headlights has nothing to do with the Jeeps ability to perform, rather it suggest that the old way of doing things was much better then the new. The same scenario is UN-folding with the new diesel technology, these newer, lighter and more powerful diesel engines will draw many criticisms. Truth is, Cummins completely change the standards to which they build these engines, the new V-8 diesel engines are built with much stricter tolerances and will run faster, stronger and make much less pollution then the current ISB. If you thought the Cummins was dependable, then these new versions will raise that bar significantly, higher build standards, closer tolerances and new manufacturing methods will all be in place to make sure these new versions of the Cummins diesel engines uphold the title as the worlds most trouble free engines. I look forward to the future, and wish who ever it is that signs with Cummins, the best of luck.