(August 8, 2011) SANTA MONICA, Calif. — When motor oil turns black, is it no longer safe to use? Do you need to change your oil after 3,000 miles? Edmunds.com debunks automotive urban legends — and helps consumers save money — in a new article "Top 7 Urban Legends About Motor Oil."

"Oil in today's cars should be changed at the designated intervals in the owner's manual or when the car's oil life monitor light flashes," said Phil Reed, senior consumer advice editor at Edmunds.com.

"By following their manufacturers' recommended maintenance schedules, car owners can actually save lots of time and money with less frequent visits to maintenance shops."

Edmunds.com found that oil chemistry and engineering has evolved so much in recent years that the average interval for 2010 model year cars is around 7,800 miles.

The "3,000-Mile Rule" is just one of many common myths exposed by Edmunds.com. Other oil myths debunked by Edmunds.com include:

    MYTH: Nearly all cars should be serviced under the "severe" maintenance schedule. When manufacturers say "severe," they generally apply to vehicles that pull heavy trailers, or commercial vehicles that can idle for hours at a time. Plain old stop-and-go traffic doesn't automatically bump people into the severe schedule.

    MYTH: Check the oil on the dipstick. If it's black, change the oil. Experts say that oil is meant to get dark — it means it's doing its job. Also, different additives can change the color of motor oil.

    MYTH: Once you use synthetic oil, you always have to use it. "As long as the oil meets the service and viscosity requirements set out in your owner's manual, you can switch back and forth as much as you want," says Edmunds.com Engineering Editor Jason Kavanagh.

For detailed explanations explaining all seven urban legends about motor oil, visit Edmunds.com.