uh oh - this is very important information concerning the oil change -
"basically drive the 7 miles to work and back"- this is the reason that you need to change the oil at the 3k interval. You have to understand that this is one of the worst things you can do in regards to the oil. You see, you do not get the temp up enough to boil off the condensate. By all means, change it at 3k and the high quality, non-synthetic is fine. OT - if you only drive 7 miles to work why don't you ride the bicycle?
My commute is 40 miles one way, if it was 7 I would definitely be on the bike.
engatwork
'95 E320
'97 Honda CRV