You’ve seen the power of my 1-8-4-3-6-5-7-2 firing-order T-shirts for starting conversations, now get yourself a D/F Four-Stroke T-shirt!

Intake. Compression. Power. Exhaust. The four stroke Otto cycle. It’s the rhythm upon which we anchor our whole lives. Without this, we make no thunder and smoke no tires. I guess you could find other ways to smoke tires, but why would you? (I mean…gasoline forever, right?)

Show the world your love of internal combustion! The Intake Compression Power Exhaust lettering is centered up front, with the larger piston design on the back. These shirts are black, 100% cotton, and made in the USA.