Sorry to be so long getting back. Yes, I change filter every 3,000 miles and add what the filter drops (usually 1/2 qt.). I've been doing this for years with M-1 (Ford ran a test when M-1 first came out, drove a Lincoln 100-K with no filter or oil change, and could find no engine wear of concern on tear-down). I've done this with cars and trucks, I drive about 20-k a year on mountain roads and my engines are clean and sweet running and last a long time. Our last trade-in, a '98 Buick with 170-k, never ran better than it did the day we traded it. My '03 Pontiac is over 95-k now and ticks over nicely, as the Brits say. I've also used this in cars I didn't buy until they were over 100-k. After the first change, when the engine would absorb about a quart before the first filter change, the engines always ran cooler, quieter, more efficiently (measuring mpg).