NEW YORK (MainStreet) -- Urban legends aren't exclusive to Bigfoot and the ability of Leprechauns to find gold. The car repair business is loaded with myths too, and left un-debunked (bunked?), they can hit you in the wallet big time.

Chances are, you don't want that -- not in this economy.

In fact, according to

data

from AAA, one in four drivers can't afford a $2,000 auto repair bill right now. What's more, about 50% of all

American car owners say

they are "hanging on" to their older vehicles, knowing full well that the "baling wire and duct tape" approach may be the only thing standing between them and a fat auto repair bill they just can't afford.

Because pretty much any car repair will set you back hundreds of dollars, it pays to know which problems are worth fixing and which to let slide.

The trouble is, even the average repair for a "

check engine light

" issue costs just over $300, according to

CarMD.com

, and standard repairs can easily go over $1,000. AAA adds that a transmission repair can cost between $2,000 and $4,000, while a larger engine problem can cost $5,000 or more.

Knowing what myths and legends exist in the car repair world may potentially save you hundreds, if not thousands of dollars. Here's a handy list to keep in your glove compartment and break out the next time something's wrong with your wheels:

So much for the "3,000-mile rule"

Edmunds.com says that the 3,000-mile oil check is a thing of the past.

Most new models

-- 2010 and older -- can go 7,800 miles before an oil check is needed.

Dipstick check

The common refrain among car cognoscenti is that you check the oil on the dipstick. If it's black, change the oil. But Edmunds says that "oil is meant to get dark -- it means it's doing its job. Also, different additives can change the color of motor oil."

It's not the gas cap

CarMD.com reports that, for the first time since the advent of on-board diagnostics, the gas cap is no longer the top fix for "check engine" problems. "In fact, four of the top five fixes (replace O2 sensor, catalytic converter, spark plug and mass airflow sensor) are related to vehicle durability," the company says.

Careful on the brake fluid

This tip from

Consumer Reports

addresses a common myth linked to brake fluid. If It's low, the conventional wisdom says to top it off. Not so, says

Consumer Reports

. Instead, get to an auto repair shop and head off a potentially big problem with your brakes by getting them checked immediately.

Stretch out a battery charge

Years ago it might have been accurate to charge a dead battery for a few minutes before pulling the plug. Not today, as newer vehicles power more than just an engine -- they now light up iPods, "hot" seats, GPS devices and televisions. So leave that charge running longer -- even for a half-hour. If it doesn't hold a charge by then, get the battery checked out.

There's no need to fall victim to costly car repair fairy tales. Keep a sharp eye out, and take good care of your vehicle.

>To submit a news tip, email:

tips@thestreet.com

.

Follow TheStreet.com on

Twitter

and become a fan on

Facebook.