Summer-ready: A little prep work can save you cash and boost your fun

Thule's Raceway Bike Rack is light enough to remove when not in use -- a big gas saver. (Thule)

The Pioneer AVIC-X930BT In-Dash Navigation AV Receiver features built-in navigation and audible Facebook updates. (Pioneer)

Whether or not gas prices are throwing a monkey wrench into your road-trip plans, it's still time to get your car ready for summer driving -- below the chassis, under the hood, in the trunk and on the dashboard.

A bit of precautionary maintenance now can help prolong the life of your car and make the next few months safer, cheaper and more fun. Ray Cox, an expert mechanic with AutoMD, a California-based online auto resource and consumer advocate, says the first thing he checks going into summer is his tires.

"Tires are No. 1," he says. "Tire pressure is going to save you gas mileage."

Make sure your tread depth is at least 1/8 inch, and check your owner's manual for the proper air pressure. If you need to replace your tires, consider getting low-rolling-resistance tires, which can save up to 6 percent on your gas usage.

Under the hood, the priority is checking all of the fluids. Get an antifreeze tester at an auto-parts store and check the pH of your cooling system. It should be a 50/50 mixture of antifreeze and distilled water.

Change your oil as well. Switching from an all-weather motor oil to a higher-viscosity synthetic can make your engine run up to 2 percent more efficiently. "Every little bit helps," Cox says.

And don't forget about the wiper fluid -- all those tiny bugs stuck to the windshield can add up to dangerous blind spots.

In the trunk, Cox recommends a good emergency kit that includes a flashlight, jumper cables, duct tape, a reflecting triangle and a Leatherman tool or Swiss Army knife. As appropriate as it seems to make a cooler and golf clubs permanent summer trunk fixtures, Cox says that can add about 70 pounds of weight and drag to your vehicle.

Likewise, the bike, kayak and luggage racks that Seattleites love to affix to their cars for a quick weekend getaway are bad news for gas mileage, adding extra weight and wind resistance. Look for a light rack that's easy to mount and dismount, like Thule's Raceway bike rack ($220-$230) or the new Yakima HighLite ($299-$329), which weighs in at just under 20 pounds.

Even driving with your windows down can affect your gas mileage. "At high speeds, it's more efficient to turn the AC on and keep the windows closed," Cox says. "Around town, though, it's better to keep the windows open, or just run the fan."

When the windows are open, you need more from your car stereo. For those looking to splurge, Kelly McDaniel, director of Mobile Electronics for Car Toys, recommends the Pioneer AVIC-X930BT In-Dash Navigation AV receiver ($800). It has built-in navigation, Bluetooth, full control of iPod audio and video, and an app mode that allows you to get audible Facebook and Twitter updates through your car speakers.

If that's a little more toy than you need, the iSimple GateWay interface devices ($190) integrate your iPod/iPhone with Bluetooth and HD or satellite radio.