My son drives over the road. He's got a company truck, an '05 Columbia. I just called him, he's on his way from Montreal to Iowa right now. Anyhow, he said he would guess they turn even more than 50 degrees. He hasn't ever measured it but he said they turn pretty far. He's not going to be stopping until 2330 tonight and I don't think he wants to get out and try to measure it. He thought maybe you could find the spec somewhere on line. Maybe tomorrow he'll crank it all the way over and try to guess the angle. I don't know how you'd measure it. How would you without any fancy guage or something?