Break in oil is exactly what it says - break in the engine then change it. Break in oil does not have the detergent levels of a standard race oil . It was originally designed to break in the motor on the dyno and be changed out. If you follow NASCAR engine builders - they run the engine in break in cycles on the dyno then drop the oil and replace with oil that they intend to run for actual dyno pulls. Personally I would not run a break in oil more than a couple of passes if you did not dyno the motor.