I'm 2,500 mi into my 4k OCI with Pennzoil Conventional and I'm going to drive 1,500 miles over the next two weeks to NC and back to CT. My daily commute in CT has been 4 miles each way, with a few 1 hour trip during the last 1,800 miles. The '06 Chevy hangs on the high when starting at temps below 32°F and the OLM clicks off %'s pretty fast while on high idle. Given these conditions: do I change the oil before, during, or after the trip?