Most V-6 engines have 4 crankshaft main bearings, with two connecting rod sets between each main bearing. Most inline-6 engines have 7 main bearings, with one connecting rod in between each. For this reason, the bottom end of an inline-6 is more stout, and is therefore less prone to breakage.
Also, there's the ol' trucker school of thought that says that an inline engine has more low-end torque than a V engine. Many people of this school of thought actually believe that an inline-6 engine will have more low end power than a similar-sized V-8. If you look at the power difference (or near-lack thereof) between a Cummins B5.9l (359ci or 5.9l inline-6) and an International-Harvester T444e (444ci or 7.3l V-8), this will help illustrate the idea of an inline-6 as compared to a V-8. Chances are, the higher low-end torque numbers are due to the increased rotating mass (as an example, the crankshaft alone on the Cummins B-series straight-6 weighs 125lbs
).
From a truck guy's standpoint, I've always seen V-configured engines as a good engine to have for high speed, and inline engines as a good engine to have for low-end power. This is ironic as my F-250 has a V-8 while my Benz has an inline-5. It ought to be the other way (straight-8, my truck would have a
loooooong hood
)...