My sister ran that XL 10w30 stuff in her 95 Honda Accord for 9 months and approx. 18k miles with an Amsoil filter. Vehicle now has 198k miles. They've been busy getting house ready to sell, and vehicle maintenance was not on her mind. Mix that with several trips to FL and NJ, and she was WAY behind on her oil change. At least her husband was checking the oil for her and keeping it up. She brought the Honda over to my shop this weekend with some more XL and an SDF 20 and I changed it for her. Oil was down 1 quart before I drained it. It came out really dark, of course, but with no chunks or debris. Engine is still quiet and still looks clean inside oil fill hole on the valve cover. I guess he must have added 3 quarts during that run, since the 12 qt. case had 5 quarts left in it. With a 4 quart sump, that leaves them 1 extra this time. This engine seems to be consuming (no leaks) about 1 quart of oil every 4500 miles. That should work out good for a 7500 mile run this time.
My point is, while running the XL oil and filter that long was not recommended or smart, apparently it still protected the engine reasonably well and is probably one of the better group III oils out there. And yes, I know, I should have cut the oil filter apart to see if it was torn inside and sent a sample of the oil off to see that it was totally shot.....for all my fellow BITOGers. Sorry, not this time.