In this economy, almost everyone has trimmed the household budget. But you don't need to overdo it with the scissors. Certain cuts might save you $25 or $50 today but cost you thousands later.

1. Your car

Cuts that cost you:

Skip your regular oil change and you save $25 to $30. But those savings could be temporary when aging oil damages your engine.

Worst-case scenario: You'll need a new engine, which could cost $5,000.

"Old oil turns to sludge, and you have restricted oil movement through the engine," says Jeff Ammons, the owner of Howard Motor in Williamsburg, Va. "Dirty oil is bad for an engine."

There is an added benefit of a regular oil change. While getting it changed, your mechanic will check all the fluid levels in your car, helping ensure your safety on the road, Ammons says.

Skip getting your tires rotated and pressure checked and save an additional $25. But beware the consequences if you ignore your tires, Ammons says.

Worst-case scenario: You could be in a wreck, creating huge mechanical and medical costs.

"A lot of accidents are caused by not enough air pressure," Ammons says.

Paying extra attention to your tires has other benefits as well. Rotating tires helps them last longer, delaying the day you have to spend hundreds of dollars on replacements. The right pressure also improves gas mileage, Ammons says.

Cuts that count:

Improved spark plugs and computerized fuel injection mean you can lengthen the time between tuneups, Ammons says. Savings: $250 to $500.

"If the car is running well, leave it alone and do the other things that have to be done," he says. "Usually I end up talking customers out of a tuneup because I find something else a little more important."

If your car engine starts running rough or vibrating, bring it in for a tuneup, Ammons says.

2. Your medicine cabinet

Cuts that cost you:

When you consider the cost of medications, you may be tempted to skip doses of your medicines for lowering blood pressure or cholesterol and double the life of that prescription. Unlike some illnesses or conditions, high blood pressure and high cholesterol don't normally produce daily symptoms. But you may shorten your own life.

"You do see people skipping doses," says Sophia De Monte, a pharmacist with Costco in Melville, N.Y. "Instead of taking a medication every day, people might take it every other day just to make it last a little bit longer. With high blood pressure or high cholesterol, you don't feel the changes in your body."

It's true that you're potentially saving half the cost of the medication, but it could cost you down the line.

Worst case scenario: a life-changing or life-ending heart attack or stroke.

"You're putting your health at risk," De Monte warns.

Cuts that count:

That being said, you can save on prescription and over-the-counter medication by thinking about your medications before you go the pharmacy.

Start at home. Your health insurance company likely releases a list of medications and how much your co-pay will be. Bring that guide to your doctor to refer to when writing a prescription, De Monte recommends. "There may be a similar medication you can tolerate at a lower co-pay," she says.