05 Expedition with 180k miles, since 2 month period of time , I place all brake , new coolant ( motorcraft ), fuel filter, air filter..... rear diff I replace with valvoline 75w140, but I had to add half quart of OLD OLD ( 4 year old ) redline 75w140, should I change this out ? expy run and drive good, very smooth in town and highway. All good tires. Anything I should check before this trip, about oil I change it month and half ago with mobil super 5000 , I roughly put 1100 miles on it. Should I leave it alone ? anything I should add in fuel tank on this trip ? or tool to bring on this trip ? 13 hours each way.