Undoubtedly, diesel engines dominate heavy-weight vehicles. But what happens when their hearts stop skipping a beat? A murky or maybe contaminated fuel, an inefficient air filter, or an oil change overdue-all it takes. Before you know it, the powerhouse fleet you owned could soon end up running into serious trouble. So, what now? Routine diesel engine maintenance. Heavy vehicles-well, trailers, buses, large vans, and others-just to list a few-are another world when it comes t