Mileage is 30% in-town, 10% unloaded highway, 60% towing highway. Tow miles are either with a 4000lb flatbed or a 9000lb enclosed, mostly with the big enclosed. Thoughts on the wear? Truck has 175k on it now, with 5k on current oil. I am going to change the air filter and the oil and send another sample before my trip this weekend.