Here are the results of a 10,988 mile OCI using Mobil 1 5W-30 over approximately 9 months. The first 6000 miles were with a Napa Gold filter, then I switched to a MicroGreen filter for the last 5K miles. These were mostly highway miles, with about 600 miles of trailer towing on my '03 Toyota Highlander with a 3.0 V6 engine. If you want to check out pictures of the dissected filter, go to the Bypass Filter Forum.