Some tales die hard and this is one of them. Years ago, with the machining, materials and oil products of the day, it did take a long time to break in, or wear in (more appropriate term) engines and drive trains. Now days, thanks to superior machining processes, more advanced materials and vastly superior oil, that process is much quicker, but the end results are the same, which is to say diesels have a longevity that can't be denied. By a huge margin, owners will get tired of their truck long before they wear out it's engine and drive train.