GM compares the Chevy Spark with the average American sedan in the early 1970s.

Here’s how the city car stacks up:

• Exterior - The mini-car is 50 percent smaller than the typical ’73 American full-size sedan.
• Height - New subcompacts like the Chevy Spark are actually 6 inches taller than the 1973 sedan.
• Wheels - The wheels on the new 2013 mini cars and the 1973 full-size cars are equal – both maintain their poise on standard 15-inch rims.
• Interior - The 2013 subcompacts have front and rear headroom and front legroom that match the average 1973 American full-sized sedan.