Back in the days when I worked at the quick lubes, Valvoline came out with MaxLife high mileage oil and claimed that it would slow and even stop oil leaks.  It works by using added detergents and seal swellers, and Valvoline really pitched it as the next best thing.  Well, I couldn't convince anyone to pay extra for the stuff, so my 20 cases sat in the basement next to the other crap that wouldn't sell.

 

We then offered it to a good customer, at no extra cost, who had a small oil pan gasket leak, just as an experiment.  The next time he came in for an oil change, we anxiously ran downstairs in the pit to see if it worked, and behold, the damn stuff actually stopped the leak!  This gave me and my team some added confidence, and finally we were able to upsell high mileage customers.

 

My Acura is just about to roll 100,000 miles and I added this high mileage oil into my last oil change.  The stuff is not as expensive as synthetic oil, and does add some value, and actually benefits your engine.  Something to consider for you people out there who refuse to buy a new car and plan to run your current ride into the ground.