People on tight budgets are often tempted to skip some routine car maintenance services, or at least to delay an appointment with the auto shop.

However, poorly maintained vehicles cause thousands of wrecks each year. The bill for accidents resulting from unperformed vehicle maintenance tops $2 billion a year, according to the Car Care Council, an advocacy group based in Bethesda, Md.

Even if you are lucky enough to avoid a crash, putting off maintenance is likely to reduce your car's lifespan.

"If you don't maintain your car, you're taking a vehicle that might have been driven for 200,000 miles over its life, and you're knocking it down to maybe 150,000 miles," says Philip Reed, author of the "Strategies for Smart Car Buyers" blog at Edmunds.com.

The true cost of not maintaining your vehicle can include hefty repair bills for bad brakes, failed emissions tests and maybe even a failed engine. Following is a list of some common maintenance requirements for automobiles and the costly problems that can occur if they aren't completed:

6 Car Maintenance Must-Dos
1. Consistent oil changes: Regular oil changes help keep your engine clean and lubricated, says Deanna Sclar, author of "Auto Repair for Dummies."

"Oil cuts down on the friction that can literally wear away the parts of the engine," she says. "One of the most important maintenance-related things you can do is change your oil frequently."

There is some debate about how often drivers should change their oil. Many car experts recommend getting the work done every 3,000 miles or three months, especially if you often drive in stop-and-go traffic or your car idles for long periods of time.

However, some car manufacturers recommend longer intervals between oil changes. The safest advice is to follow the manufacturer's recommendations for your specific car.

"The definitive answer is to check your owner's manual," says Vyvyan Lynn, author of "The Complete Idiot's Guide to Auto Repair."

"Few people read their owner's guide, but it's golden."

Cost of skipping: Potential engine failure.

2. Tire rotations, air pressure checks and tire alignment: Rotating tires -- switching the tire position from front to rear and vice versa -- helps them wear equally. A tire rotation should generally be done every 6,000 miles, or as often as the car manufacturer

Next: An unlucky car could suffer severe engine damage. >

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