For what it's worth, my Ranger is a 98 that I bought in 2000. First oil change, I put full 20W-50 in it. It's had nothing but 20W-50 year round for 19 years. Never had a problem. I also run 20W-50 in both of my motorcycles. One is a 2006 that I bought new, the other a 2008, also bought new. Nothing but 20W-50. EVER!
I'm on the fence with my 2004 Ford Lightning. I use the specified 5W-20 when I change it. but use 20W-50 to top it off when needed. The 98 Ranger, IIRC, called for 10W-30 on the stock oil cap. So 20W-50 is not out of the question at all. My Lightning, the oil cap says 5W-20. But the reading I've done says the thin colored water oil is only required for manufacturers to meet their CAFE (Corporate Average Fuel Economy) requirements. Some asshats in oil change places try to tell me my 98 Ranger is a 5W-20 vehicle. I'm like, "Dude, 5W-20 colored water oil didn't exist in 1998. Asshole." So, I change the oil in my vehicles at home in my garage. Their loss is my gain. I get the oil I want, they lose my business. It's all good!