Originally Posted by Reciprocal

Fair enough Lou, but here's the thing. You like synthetic, so do I. There's people here advocating extending the oil change interval to 10-12k miles because it's so good.

Here's what I suggest. At 5k, drain that synthetic oil out into a clean pan. It's going to be very dark because of all the impurities held in suspension. Now take 10 quarts of new, conventional dino oil. You gonna tell me if you had the choice, you'd rather put that old dirty oil back in for another 3-4 months rather than the new? And what about the filter? That's the judgment being made, that at 5k miles, used synthetic is better than new dino, and people are willing to run it to 10-12k miles so that the economic argument can be made that it pays for itself.

Whose warranty do you want covering your car if there is an engine problem, Lexus or Blackstone because they told you to go beyond the recommended oil change interval?

I've been through the Blackstone debate before. It's great information, and I've seen ample instances where they make the SAME recommendation to EXTEND the oil change interval for NON-synthetic oils.

The choice for me is between paying for the extra protection of synthetic but wasting money since I'm going to change it before 5k miles versus more frequent conventional oil changes on the manufacturer's recommended schedule.

I know for me, synthetic is a waste of money. If you need the extra peace of mind, by all means go for it.