As many of you know, I have been changing the oil on my HCHII at approximately 10K intervals. I recently completed the 30K maintenance of the car and have received the oil sample test for the last fill. That fill ran a little longer than usual at over 11K miles.

Below are the results of the test. I have been using Mobil1 0W-20 in the car since the 10K maintenance, and the Civic engine seems to like it. Notice the decrease in Silicon from the initial fill, indicating that it does take a while for all of the residue from the manufacture of the engine to work its way out. For those that are skeptical of longer oil change intervals, here is proof that it is the responsible thing to do and will cause no damage to the engine. By using the engine oil for a longer interval, you are saving money, and more importantly putting less waste oil back into the environment.