I have read a article in an ag publication talking about diesel engine life. The guy that wrote the article was a long time diesel mechanic. This guy worked on everything from diesel locomotive engines, to big field farm tractors, to small compact diesel tractors. The one thing this guy noticed was the most cylinder wear was in the small compact diesel tractors,or he called them task tractors that were ran a hour or less each day.The big engines that ran hour after hour or sometimes days at a time, the cylinders looked almost new. He did some investigating on starting a cold diesel engine,what he found is when a diesel is warming up there is a "danger zone" that a diesel goes through.I am not exact on temps, but he said around 110-160 deg, diesel fuel forms a acid which will slowly etch your cylinder walls. He suggested some warm-up tips for diesel owners. Make sure your thermostats are working properly, cold climates plug your block heater in, try to get through the "danger zone" as fast but safely as you can{fast warm-up do not let it idle long when cold). Do your oil samples, a nd change oil often if you do alot of cold running.