Recently I changed oil in my 06 camry with 165K miles and switched to maxlife HM 5W-30 oil (got a good deal). Prior to this I always used mobil super 5W-30. After putting about 500 miles on the new oil I had to leave for a business trip for 2 weeks and the car sat without being started. After returning the 1st time I started it the car smoked heavily for about 5 minutes and then started to taper off until now it is barely noticeable a couple days later. I checked the oil level and it was still fine, but noticed it was almost a mustard color when wiping off the dipstick whereas the mobil tended to just have darker shades of brown throughout the service life of the oil (maybe this is typical for maxlife). My questions are what do you think caused the heavy smoking (sitting idle for 2 weeks, the switch to a different oil, or something totally unrelated). Looking through the cap I do see a little varnish on the valve cover is it possible the maxlife is cleaning this off and caused some of the smoke or the mustard colored oil (IF so should I reduce the OCI of 5000 miles I usually do?)