You certainly may replace the Auto-Rx if you are burning oil at an astronomical rate, such as a quart every 700 miles. However, it is not normally necessary. For example many times oil burning occurs from the oil control and intermediate piston rings getting coked up and somewhat welded together. At this point neither ring is functioning properly, and can be the cause for oil burning. In this situation, Auto-Rx is quite effective in freeing up the ring packs in the first 500 miles of driving in the cleaning mode of the application. Therefore, it would not be necessary to add any more Auto-Rx. Oil burning can also be a result of dirt and contaminants that have collected in valve guide and valve seal interface. This area will clean slower than the piston ring area of the motor due to less oil flow and less pressure. There are also oil burning causes that Auto-Rx cant help such as non operational PCV or crankcase ventilation systems. Obviously Auto-Rx can not adjust valves, etc. There are also deposits that might form on the valve sealing interface that should be corrected by running cleaners through the fuel system, typically where the oiling system should not be present. Auto-Rx can not clean where oil does not flow.
There are many motors that are sludged up to the point where oil passages back to the sump from the top end of the motor are clogged off. In these situations Auto-Rx can not work because there is no flow. In these cases the valve train is flooded with oil and the likely hood that the oil gets sucked past the stem seals into the combustion chamber can not be corrected, without either a head replacement or manually cleaning the head.
I dont know much about what your current needs are and how best to apply Auto-Rx. Fill us in. Many times stem seals once cleaned up with an ARX cleaning and rinse with conventional oil will perform at a higher level. Obviously a cracked or damaged valve stem seal can only be repaired by replacement. Many folks have had some luck with running high mileage oils after running a cleaning and rinse. High mileage oils have ingredients that swell the stem seals and can mask a worn situation. I will mention that these oils perform best after a cleaning and rinse with conventional oil and Auto-Rx. You want the swelling agents in the high mileage oil to have a clean seal to work on so that it is swelled evenly.
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