10000 miles plus on oil that looks clean so you think you don't need an oil change? the only thing this means is the oil is not doing its job ofcleaning the engine . if oil is a little dark at 5000 miles it means the oil is doing its job. time to change it. go with 5000 to 6000 miles between changes. you cant go wrong. just like spark plugs oil is better now too. you don't change your spark plugs every 12000 miles like to did in the 60s do you?