What oil is used for 1997 ford explorer - 1997 Ford Explorer AWD

Factory says 5W-30.
You can do better with Walmart's full synthetic 5W-30 with a filter and oil change every 5 - 6,000 miles.
Just keep an eye on oil level - the V8 version of this vehicle does use oil after about 120,000 miles. The 6 is a bit better until about 150,000 miles.

Use the oil specified on oil fill cap, I would expect 5w 20 or 10w 20. Even with high mileage USE THE SAME weight oil. Thicker oil (yester year thinking) is the wrong answer if you consume some oil.

There is a high mileage blend, Casteroil has one, that actually does reduce consumption...BUT use the specified weight for your car..

Really depends on your average temperature of your climate and the season. Real hot places and the manufacture suggests a thicker oil , real cold places and they want thinner oil. Check the manufacture Web site . I will tell you Ford's have 2 small handicaps.
1. If you have an adjustable steering wheel the linkage system they used on the ignition jams up in cold weather.. The first thing people want to do is turn harder.. It works 1 or 2 times then you cannot rotate past accessory mode. Expensive to fix . I just put a door bell switch in mine. Rotate to accessory and push the doorbell.
2. If it's cold out and you drive the truck for a short distance and turn off the motor go in shopping and return they don't like to start. Open the hood , pop the air breather on top of the engine... inside where the air goes into the engine there is a flap in the closed position.. It's the choke... get a cigarette package roll it up like a sub sandwich, wedge that flap open with the cigarette pk .. Fire up the truck... it'll start right away but make sure no one is standing in the engine area cause if it's real flooded it may spray a flame for a second