tube or pipe

i have used the pipe b4 and it welds the same but i use coreflux ..and i know im gona here shit about that to

I'm quite sure that black pipe is plenty strong enough to do what a daily driven vehicle needs. But what I would like to point out is that balck pipe is referred to as black pipe, period... and tubing will be adressed as 1015, 1020, 4130 or 4140 meaning that you can decide what strength material to use as well as the size, unlike black pipe that is similar to 1015 only, you just use thicker or thinner material if it needs to be stronger.