Honestly I'm about at that point with my 5.4 ... It's really started to go through oil. I do have the right side head gasket leak and RMS leak, but it doesn't leave drops on the ground, so it's consuming it all. Very worn out, 235000 (somewhere near there) miles. Maybe 236/7k? I'd have to do the math again. (I stopped using TCW3 a while back once I ran out, may try it again to try to slow it down a bit). When towing I go through a quart every 100 miles and empty it's about 250 miles per quart. I think the next change I'm going to catch the oil out of the Subaru and just put it in a 5 quart jug and start dumping it in the F350 when it needs oil.