...Truck without a man's help? I'm guessing its less than 1. I know most will say they can do it, but in real life, most probably can't get the truck jacked up, let alone loosen the lug nuts, or lift the spare out of the designated place (depend on truck design), or lower it from under the truck...
I.e., I see that a semi-trailer/truck can weigh a maximum of 80,000 pounds. How many gallons of cargo (whether it be milk, gasoline, chemicals, etc) does the typical tank trailer hold?