, the largest seller of diesel-powered vehicles, has kept its oil change costs close to those for gasoline engines, other makers present a different picture. Fiat Chrysler’s 3.0L eco-diesel engines, for example, require a very specific grade of synthetic oil and a high-priced filter, bringing those oil changes close to the $200 mark at dealerships. Almost all modern diesel engines require synthetic oil and larger displacement V6 and V8 diesels require more than twice the amount of oil as compared to their gasoline cousins. Diesels are now just as complicated and electronically controlled as the most advanced gasoline engines. When they represent a small fraction of vehicles on our roads, how much experience do you think technicians actually get on diagnosing and repairing this technology? Many carmakers now require a very detailed step-by-step process be followed when repairing diesel engine faults under their warranties. They, like their customers, find it expensive when parts are replaced on a trial and error basis.