Your Toyota oil filter is one of the least expensive and most often replaced engine components on your vehicle. It can be located on the lower portion of the engine block and is generally accessed from under the engine by the person changing the oil. The recommendation of changing the oil filter on your Toyota engine is to be done after every 3,000 to 5,000 miles of driving. If your Toyota is driven in heavy traffic with a great deal of time is spent idling like a New York City taxi, then more frequent changes should be done. The miles are just a reference point for the owner to know when the oil filter on their engine is approaching its saturation limit of collecting particulates from the oil. These particulates are created internally from the combustion of the fuel that powers your engine as well as from the friction of the internal components rubbing against each other. When the oil filter reaches it saturation level, the check valve located on its intake port closes. This is a bypass valve that will make it possible for the oil to continue to flow in your engine. If that was not to happen, because of the saturation of the paper element in the Toyota oil filter being reached, the flow through it will be reduced. This will basically starve your engine of lubrication causing excessive wear on the moving parts in the engine. This would damage not only the pistons and cylinder walls but also the bearings on the crankshaft. The owner of a Toyota should not be under the impression that just because the oil filter is inexpensive that its task in keeping your engine running correctly is not essential. Without this small component, an engine would not be able to last for the 100,000 miles or more that they currently do.