Two to four weeks before you goGet any major repairs done. If your car needs major repair or maintenance, do it at least one month before you go. That will allow plenty of time for any problems related to the repair to pop up.
Check the coolant. If your destination is a lot warmer or cooler than home, check (or have your mechanic check) the coolant's mixture of antifreeze and water to make sure the car is properly protected. If the coolant needs to be changed, do it (or have it done) now.
Check the tires. Make sure your tires are inflated to the proper pressure. Low pressure can cause extra heat buildup that can lead to a blowout at high speeds. Follow the instructions for checking tire pressure in your owner's manual. While you're down there, check the tire tread. Put a penny, edge on with Lincoln's head pointing down, in one the grooves of the tire. If you can see the space above Abe's head, it's time for new tires.
Check the spare tire. Make sure the spare is fully inflated and that the jack, wrench, and other tire-changing bits are in the trunk. If your car has wheel locks, make sure you have the adapter for the lock-nut.
Check the glovebox. Check for the owner's manual and registration. If the manual is missing, consider ordering a replacement before you go. Some automakers have manuals in PDF format on their web sites. Check the registration to make sure it won't expire during your trip. Consider carrying it in your wallet in case the car is stolen.
One week before you goGet any scheduled maintenance done. If you think your car is going to come due for an oil change or other maintenance during your trip, get it done now.
Check the tires again. The tire pressures should be about the same as they were last time you checked them.
Clean out your car. The more stuff you haul, the more fuel you burn. Clean mercilessly. If you're going to the Grand Canyon in the summer, do you really need those snow chains? My rule: If in doubt, take it out. If you miss anything in the next 6 days before your trip, you can always put it back.
Check the air filter. A clogged air filter reduces fuel economy. They're inexpensive and easy to change. If your current air filter has been in the car for more than 10,000 miles, it's time to clean it or change it.
Buy a road atlas. If you don't have a current road atlas, get one. Hours and hours of expressway can get boring. Getting off the beaten path can add an entirely new dimension to your trip.
Join AAA. If you don't have some sort of roadside assistance program, consider joining AAA. They'll tow your car if it breaks, change the tire if it goes flat, jump start the car if the battery dies, open the doors if you get locked out, and give you gas if you run out. An AAA membership will usually pay for itself the first time you run into trouble -- plus you'll get discounts at some roadside motels and restaurants.
One day before you goWash and vacuum your car. Before you pack, give your car a good scrubbing and vacuuming. Clean cars always seem to run better. Besides, who wants to travel in a dirty car?
Check and change the tire pressures. Yep -- tire pressures again! Many cars have two recommended ratings, one for light loads and one for heavy loads and/or high speeds. If you're taking the whole family, visit your local gas station and inflate the tires to the higher setting. You will find this information in the owners manual or on a sticker in the door jamb or fuel filler flap. Remember: Set the pressures when the tires are cold.
Fill the gas tank. Might as well get it out of the way now. Besides, gas is often more expensive on the road.
The day of your tripLook at what you've packed. Open your suitcases and take one last look -- do you really need all that stuff? If there's anything you can do without, then do without.
Load evenly and carefully. If you're carrying lots of heavy objects, position them forward in the trunk and distribute the weight evenly side to side. Cars don't have unlimited carrying capacity, so don't overload.
Relax! Unexpected things can happen, but if you've followed these guidelines, you've headed off a lot of potential problems. Relax and enjoy your trip!