To smoke a pipe I need to be calm, not to be aware of anything, I need to relax. So it means that I smoke when I don't work or when I have a weekend off. This translates into a minimum of about an hour or more. I also smoke slow, I let the pipe rest, I never let it overheat, or I try to. And I don't have very small pipes either. Sometimes I don't finish the smoke, and pick them up a few hours later, or maybe the next day. This is like, how long the fuel lasts in your car, engine size, age, heat, and size fuel tank, fuel quality, etc. because I imagine that size, needs and the training, technique, way, mania, of driving that you have. You can drive pissed off, sleepy, happy, not in a hurry, nervous, and all this you transmit to the vehicle, the truck, the bicycle, the motorcycle, even to the barbecue at home, lawn mower. There is also the climate of your area, type of tobacco, whether you like to smoke it moist, dry or crisp, quality, and other variants. This is the only thing I can say as a pipe smoking rookie.