There's a new trend among websites offering tips for saving money in the face of the rising cost of gasoline (the cheap stuff is hovering around the 4.00 mark in certain oil states, but for most of the rest of the U.S. it's significantly over that ): buy a motorcycle or scooter, and save money. After all, small bikes and scooters get huge amounts of miles per gallon - certain models of Honda Rebels, for example, routinely go 75 miles on a single gallon of gas - and many larger bikes average over 50.

What these money-saving tipsters fail to convey, however, is that while those zippy little scooters can have their tanks filled for $20, if you don't already own one, adding one to your personal transportation fleet isn't going to save you money. It's going to cost you money in the long run.

Here's why:

Before you can use a motorcycle or scooter for in-town transportation, you have to own one. A small (250cc) motorcycle will cost around $3,500. Scooters range from $2,000 for a 50cc model to around $7,000 for a 250cc vehicle.

After you purchase a bike or scooter, you have to insure it. This means either adding it to an existing policy, or buying a new policy depending on whether or not your current insurer offers motorcycle coverage. Not all companies do.

Riding a motorcycle is not like riding a bike. Depending on where you live you could spend at least $220 taking a basic rider's class. Not all states require motorcycle education, but it's wise to go through it. Not only will it help reduce your new insurance premium, it will also significantly lower your risk of an accident.

You'll need to buy protective gear. It's true that not every state has helmet laws, but to ride without one is to risk certain death if you crash. For a full-face helmet and other protective clothing (jacket, gloves, appropriate footwear), you should expect to spend as much as $500.

Routine maintenance on a motorcycle must be done more often than on a car. You can expect to replace the tires at least every 10,000 miles (possibly more often), and an oil change for a 250cc motorcycle that doesn't have an oil filter will cost around $70.

Periodic service comes earlier and more often as well. The first one should be done at 600 miles, and will cost you between $125 - $200, and the second servicing, which should be done at 4,000 miles, may run as high as $500.

If after all those points the notion of getting 70 miles to a gallon of gas is still making you drool over motorcycle ads, consider this: in addition to what you spend on your new ride, you'll still be paying for insurance, gas, and maintenance on the car you already have. After all, bikes and scooters are great in balmy spring and summer weather, but what if it's raining or snowing? What about when you need to do a week's worth of grocery shopping? What if you have kids who need to be ferried from school to ballet class and soccer practice...what if...?

Take a breath, and do the math before settling on a motorcycle. Trading your existing car in for a hybrid may be the better bet. Find ways to save on gas and improve your mileage with Hypermiling techniques.