PHOENIX, Ariz. - When it comes to buying a car, Phoenix ranks ninth-worst for car affordability. According to’s car affordability index, Phoenician’s are overextending themselves to pay for a new car. Analyst, Claes Bell says a couple of factors that contributed to this ranking.

”One of those reasons was low household income and higher insurance cost,” said Bell.

If you’re contemplating a car purchase, suggests you follow 20/4/10 rule in order to avoid a future financial crisis.

The rule: Make at least a 20 percent down payment, use a loan that's four years or shorter and car payments, interest and insurance should comprise only up to 10 percent of a household’s gross income.

Based on the 20/4/10 rule for buying a car, the median Phoenix-area household can afford to spend just $19,571 on a car when the average new car cost $35,994.

A Phoenix median-income household can afford to spend $379 per month on car payments.

And if you’re considering extending a car loan beyond five years, says there are downsides.

Bell says your car purchase shouldn’t diminish your financial flexibility.

The top five metros for car affordability are:

1. Washington, D.C. (total purchase price of up to $37,223/monthly payment up to $697)
2. San Francisco ($32,286 / $631)
3. Boston ($30,863 / $592)
4. Seattle ($26,771 / $532)
5. Minneapolis/St. Paul ($26,606 / $502)

The five worst are:

25. Miami/Fort Lauderdale/West Palm Beach ($13,577 / $256)
24. Detroit ($13,913 / $273)
23. Tampa ($14,189 / $268)
22. Orlando ($15,902 / $309)
21. San Antonio ($16,433 / $324)