opefully, you'll get some tax mileage out of this column.

Turn your vehicle into a tax deduction. If you use your car or truck for business-related trips, to deliver food to your favorite charity, or even to drive the kids to the doctor's office, you can deduct at least some of the costs.

Automobile expenses incurred in your business travel are deductible either as a travel expense or as a transportation expense. (Transportation expenses are deductible only if they're incurred in a business or investment situation.)

To get the deduction, there must be a direct relationship between the use of the car and your trade, business or some income-producing activity. Examples might be driving to see some property you own or talking with a broker about your investments. If you have one car that you use both for personal and business use, only deduct the portion of your car expenses directly attributable to business use.

In allocating your car expenses between business and personal use, there are two methods you can use. The first is the mileage cost basis. Using this method, you multiply your business mileage by a standard mileage rate that is set each year by the Internal Revenue Service. For 1997, that rate was 31.5 cents per mile plus parking fees, interest, taxes and tolls.

So, for example, if you drive your car 10,000 business miles over the year, you can deduct $3,150, plus all of your business expenses for parking fees, interest, taxes and tolls. You cannot use the mileage cost basis if you use two cars simultaneously in the same business. It is allowable, however, if you use each car for a separate business.

The second method is the mileage percentage basis. You divide your business-related travel by your total mileage and take that percentage of your total expenses as a deduction. So, for example, if you drove 20,000 total miles over the past year and 15,000 of them were business-related, then 75 percent of your auto expenses would be deductible.

Included in such auto expenses are all of your business parking fees and tolls, plus 75 percent of any interest, taxes, gas, oil, repairs, washing, registration, license fees and depreciation you incurred.

There is a special tax planning strategy that you can use if you have two cars in your family. Assume that you've been using one car exclusively for business and the other exclusively for personal family use. You put 36,000 miles each year on your business car and only 12,000 miles a year on your personal car. Typically, you could only deduct the costs of using the business car.

Now suppose you switched the use of each car every six months. The combined mileage of both cars remains 48,000 miles a year. But by rotating your cars equally between business and family use, each car could have 75 percent of its expenses deducted for tax purposes. Here's how it works: Both cars are driven 24,000 miles, but 18,000 of those miles are business-related. So instead of only deducting the costs associated with one car, you get to deduct 75 percent of all of your expenses on both cars. If you're like most people, that will save you several hundred dollars a year in taxes.

There is even a way to deduct some of your routine work commutes. Typically, you can't deduct the cost of commuting to and from work. However, if you have a regular place of business, you can deduct the daily transportation costs of traveling from your home to a "temporary work location." A temporary work location is any locale where you perform services on an irregular or short-term basis. For example, daily transportation expenses incurred by a doctor traveling between a clinic and a hospital or between the doctor's residence and a temporary work location could be deducted as business-related. Alternatively, an executive or salesman who makes infrequent visits to customers or clients at their offices may deduct those expenses.

Executives or business owners also may want to think about trading in their luxury sedans for sport utility vehicles, because of the way the tax laws are written. Sport utility vehicles that weigh more than 6,000 pounds (like a Chevy Suburban or Toyota Land Cruiser) aren't considered "cars" by the IRS. That means you can fully depreciate those vehicles in just five years compared with luxury cars that have a maximum depreciation level of $14,460 over the same period.

If you have a home office, expenses incurred in getting from your home office and other job sites can be deducted. Your "commute" from the bedroom to your home office is the only portion not deductible.

The deduction for transportation expenses may potentially reduce your net cash outlay for a car to less than half its cost. For example, let's see what happens if you're in the 31 percent tax bracket and bought a $6,000 car (it's a compact, OK?) and used it solely for business purposes. You can claim the first $1,700 as a business expense and choose a five-year depreciation schedule. If you drive 30,000 miles in the first year, your net cost for the acquisition drops to less than half.

$6,000

$1,700 x .31 = $527

($6,000-$1,700) x .20 [depreciated over five years]) x .31 = $267

Net cost of car = $5,206

30,000 miles @ 10 mpg = 3,000 gallons @ $1.25/gal = $3,750
Repairs, oil, and upkeep = $900
Insurance = $1,210
Garage rent, license, registration = $750
Tolls, parking, interest on auto loan, etc. ($6/day) = $2,190

Total expenses = $8,800

Tax saving ($8,800 x .31)=$2,728

Final Net Cost ($5,206 - $2,728) = $2,478

While the above numbers have been simplified, what I want you to recognize is that your car can be a valuable source of tax-saving dollars.

If you have a car that is used 75 percent of the time for business, everything related to that car would be 75 percent deductible. That would include your new CD player and the dice you hang on your rear view mirror.

Focus on our objective here. If you can convert personal expenses into business expenses and are in the 28 percent tax bracket, you have, in effect, created a 28 percent discount on the cost of anything that qualifies as a business expense.

Suddenly, that item that was too pricey at $100 becomes a bargain at $72 ($100-28). The trick, as with many tax strategies, is to get the government to help lower your overall costs.