You should change your oil every 3,000 miles, no matter what the manual says.
Once upon a time, almost every auto manufacturer recommended that the oil in your engine be changed every 3,000 miles (4,828 kilometers). Use oil past that interval and the engine would begin to fill with sludge, which would not only degrade performance but leave the moving parts at risk for damage.
That's no longer true. Modern detergent oils, improved oil viscosities and better auto engineering in general now allow cars to go about 7,500 miles (12,070 kilometers) between oil changes. Yet you'll still hear the 3,000-mile (4,828-kilometer) figure quoted widely -- especially by people trying to sell you oil. No less an authority than Consumer Reports has debunked this myth, stating that unless you drive your car under unusually difficult conditions, and especially if you always drive it in stop-and-go traffic, going 7,500 miles (12,070 kilometers) between oil changes shouldn't harm your engine in any way.