This was a real shock. I was shown an 1984 list of tires. Remember, I have a 1987 car. Figure it out yourself. I wanted to go to a wider tire for traction in the snow, but I found out this was wrong.
Narrow tires are better in snow.
I still went to a wider tire anyway. I also have a front wheel drive and there is a lot more weight in the front than in the back. We'll see what happens. Yes it does. The error in the speedometer itself would be probably be more.