Do this every month and “you can avoid 70 percent of the reasons cars break down on the highway,” says Deanna Sclar. To check coolant or antifreeze, use the owner’s manual to locate the coolant reservoir. Then, with the engine cold, look for the embossed “fill to” line on the plastic container. Do the same for windshield-wiper and brake fluids. (Brake fluid will ruin a car’s paint, so be extra careful with it.) To check the engine-oil level, use the manual to locate the dipstick, then “pull it out, wipe it off with a lint-free rag, shove it back in, pull it out again, and read it,” Sclar says. Also make sure your oil is clean. “Take some between your forefinger and thumb,” she says. “If there are little bits of grit in it, you should go in for an oil change.”
Pros Charge: $25 or more.
DIY Cost: $2 (windshield-wiper fluid), $12 (brake fluid), $3 (motor oil), or $10 (coolant).