How many mpg does a van hold?

A van doesn't *hold* miles per gallon (mpg); mpg is a measure of fuel efficiency, not fuel capacity. A van's fuel tank holds a certain number of gallons (e.g., 20 gallons), and its mpg rating indicates how many miles it can travel on one gallon of fuel (e.g., 20 mpg). The actual mpg a van achieves will vary depending on driving conditions, vehicle maintenance, and other factors.