I purchased my 2002 adventurer a little over a year ago, and when the warm weather hit, I did the change all the fluids maintenance thing. My manual recommended 75-90 synthetic fluid. Took 13 quarts to bring the level up to the bottom of the fill hole. Lucky for me I retired from a small independent auto parts store and the owner still lets me buy parts at his cost . Mobil 1 75-90 synthetic --- $9.25 a quart. OUCH.