Fiat Idea Oil Filters From Dec 2003 to Dec 2011 Available Here. Although small in size, oil filters are a critical part of your engine's lubrication system. Unlike air and fuel filters, if left unchanged, an oil filter is unlikely to display any warning signs to the driver such as poor performance or reduced fuel economy. As oil filters become clogged and dirty, they can no longer filter the oil sufficiently and this can lead to permanent damage to the internal components in your engine such as bearings and camshafts. Changing your oil and oil filter at regular intervals if key to ensuring the long and healthy life of your engine.