Time Magazine- Corn for people vs corn for SUV fill up

In April Time Magazine ran an article that made the claim that the corn required to feed a person for a year equals the corn needed to fill an SUV.
http://www.time.com/time/magazine/article/0,9171,1725975,00.html

This dos not seem to be accurate at all.

Figuring output of 150 bushels/ year for corn/ acre and 22,204 calories/ bushel means an acre of corm produces 3,33 million calories, feeding 3.6 people for a year at 2,500 calories a day.

Food- 1 person needs 0.27 acres to get teh necessary calories from corn.

Using the same output of 150 bushels, ethanol output in gallons per acre are abot 354 gallons/ acre/ per year. www.gristmill.grist.org/story/2006/2/7/12145/81957

Figuring a 20 gallon fill up, we get 18 fillups from an acre each year.
Figuring a 30 gallon fill up, we get 12 fillups from an acre each year.

Fuel- 1 fillup needs 0.05 acres (20 gallons) or 0.83 acres(30 gallons)

This seems to be not even close to what time reports. 0.08 does not equal 0.27. That is a factor or 350% error.

Whay would Time Magazine be so inaccurate?