The editors of Popular Mechanics placed sensors inside a package and shipped it through three major package delivery firms in order to determine which company handled it the most gently. These sensors measured the vibration, temperature, and orientation to which the box was subjected. Here were their findings:
After crunching the data and averaging the number of spikes recorded by each carrier on each trip, we found that the USPS has the gentlest touch, with a per-trip average of 0.5 acceleration spikes over 6 g's. FedEx and UPS logged an average of three and two big drops per trip, respectively (see graph, next page).
Given those results, we were a little surprised to find that the USPS flipped over its Express Mail packages an awful lot, averaging 12.5 position changes per trip. Meanwhile, FedEx averaged seven position changes, and UPS had an average of four.
All three carriers did a good job at maintaining a stable temperature, but FedEx nabbed the top rating, with an average change of only 26.01 degrees, compared with 26.8 degrees for UPS and almost 32 degrees for the USPS. But the maximum temperatures our package experienced were within 2 degrees, and at no time did a temperature register above 80 degrees or below 47 degrees.
Link via Super Punch | Image: Popular Mechanics
Two quotes from the original article:
1) "we had neither the time nor the budget to make the hundreds of trips necessary for statistical significance"
2) "I was surprised to learn that, although the USPS uses its own sorting and delivery systems, Express Mail flies via FedEx. So our package experienced both the most and the least abuse while on the same airline."