Minimum Air Compressor

Years ago I had a friend and mentor who was a machinist working for Chrysler. I was on a tight budget and was looking at two compressors for my shop. I was temped to buy the smaller, cheaper unit and I asked him basically the same question. He has been passed away for years, but your question brought back many fond memories! BTW, Here's how HE answered that question when I asked:

I'm 50 years old and I've been a car guy all my life..All my friends are car guys also. And in all my years, when I've been shooting the sh*t with those friends, I 've never had ANYONE say to me
"You know? I've got a problem! My compressor is just TOO DAMN BIG!"

On his advice I bought the biggest one they had and I'm still using it 20 years later!