A couple years ago we released the original version of this shirt, featuring James Watt’s 18th Century formula and diagram for horsepower calculation. But as we would come to find, his formula and experiment was rooted in some sloppy science.

So what did we do? We put a friggin horse on a dyno. The revised version of our beloved HRSPRS shirt now features the actual mathematical equation, diagram, and dyno graph of our experiment with our new equine friend, Big D.

Find out how much horsepower a horse makes on the channel and pick up this piece of horsepower history now.

SPECS
100% Cotton
Premium Screen Printed Graphics
Real data this time