Knowledge might be power, but that's only the case if you put what you know into good use. Sure, it's a common phrase that can be used in many different situations, but when applying it to car care, weeding through the myths can result in financial savings and longer vehicle life.

MYTH: My car's motor oil should be changed every 3,000 milesIt is recommended vehicle owners follow their manufacturer's maintenance intervals while it is still under warranty. However, if your car is no longer under warranty, try using a synthetic oil that can extend your oil change intervals. The number of miles you can allow between your oil changes will depend on the way you drive and the oxidations stability of the motor oil.Oxidation stability can be measured by the American Society for Testing and Materials' rigorous Thin Film Oxidation Uptake Test. This test is so demanding it lasts 1,300 minutes. Conventional motor oils typically last less than 300 minutes, and synthetic motor oils typically last less than 500 minutes.

MYTH: A dealership must handle all maintenance on my vehicle while it is under warranty.The key to maintaining your factory warranty is that car care items specified in the owner's manual are performed on schedule. As long as the service is documented, it can be performed by any auto-repair shop. You can also do the work yourself; just make sure you keep accurate records and receipts in case warranty issues arise and for future repair.

MYTH: My car engine needs to warm up before driving.During winter months, it is a common practice for drivers to warm their vehicles up inside, but a cold engine will warm up faster when it is being driven instead of idling. If you use your car infrequently, take a few minutes to warm up your car before you drive away. This allows cold, thick oil to warm up, protecting your engine from damage. For cold weather starts, all you need is 30 seconds to ensure proper oil flow and lubrication. In the event of frigid temperatures, driving at a slower speed for a few miles will give your car enough time to warm up.

MYTH: You tires should be inflated to the pressure shown on the tire sidewall.Because of the wide variety of tires on the market today, tires can be used on more than one vehicle, so inflating your tires based on the PSI number on the sidewall might not be ideal for your specific vehicle. Car owners should follow the manufacturer's recommendations for cold weather and normal conditions. That number can be found on a doorjamb sticker in newer cars, or in the glove box or fuel door on older models.

MYTH: Are dishwashing detergents suitable for washing my car?Dish detergents are designed to remove animal or vegetable fat and will equally target the wax on your car. Instead, opt for a product specifically for automotive use.