Originally Posted By: Clevy
How exactly is dumping oil that isn't depleted and replacing it with oil that isn't depleted "cheap insurance"
Sounds more like expensive insurance considering if the tbn is at 7 and starts at 9 or 10 you've effectively thrown money out the window.
Cheap insurance,right,because the oil is some kind of risk.
Simple. Rather than spending $35 on a UOA+TBN, I spend $40 and put fresh oil in. I periodically send samples to make sure wear metals are in order, but not every OCI. If, as you suggest, I were using UOA+TBN to make sure I was getting every last ounce of life out of the oil, I'd be spending hundreds in oil analyses before finally changing the oil.
My engine spends about 25% of it's total miles at Mid Ohio Sports Car Course or Watkins Glen. Under those conditions, I'd rather have the piece of mind of KNOWING my oil is fresh, instead of wondering if the next sample is going to come back with TBN of 0.9 or KV@100C of 11.0 and wear metals through the roof. So to me, the $5 difference between sending in a sample or just changing the oil is cheap insurance.
Nevermind that Porsche re-manufactured engine is $13,000 + 30hrs labor.