Factory recommended OCI is 5K miles or 6 months. I changed my oil with Mobil 1 5W-20 and a Mobil 1 filter December 1st meaning June 1st will be 6 months. However I have only put about 2800 miles on the truck in that time. Should I stick with the 6 month rule or am I safe with the Mobil 1 to stretch the OCI further?