What allows one car to pass the 100,000-mile barrier with few repair bills, while another is ready for the junkyard? It's all about preventive medicine. "It's just like when you get to be 70 and everyone tells you the same thing: Exercise, eat right, take care of yourself," says Lauren Fix, author of Lauren Fix's Guide to Loving Your Car (St. Martin's Griffin, 2008). Feeding your car the right things and taking it for regular checkups will make all the difference.
Open the book
The key to keeping your car running smoothly is in the owner's manual, which most people ignore at their peril. "There is a schedule in the manual that runs well over 100,000 miles," says Fix, and it lists when to replace parts likely to be wearing out. The list will vary, so check your manual and follow it.
Newer cars may have the maintenance schedule built into an internal computer. A blinking light or a beep will announce that it's time to replace certain parts, says autoeducation.com founder Kevin Schappell.
"Things like the water pump and timing belt should be changed before you notice a problem," Schappell says. Replacing them won't be hugely expensive, but "if that belt breaks, it can cause internal damage to the engine, or if the water pump fails, you can overheat the engine and warp the cylinder head."
That's when things get expensive.
"Typically, around 100,000 or 120,000 miles there are some major preventive maintenance things that need to be done," Schappell says.
Get fluent about fluids
The liquids that go into your car are crucial to its survival. To extend the life of your car beyond 100,000 miles, experts suggest frequent oil changes and fluid checks done at dealerships or full-service auto centers.
In choosing oil, Fix advises buying full synthetics. They "actually will lube the engine better. It's designed for longer life. There are less emissions, so it's greener. There's slightly better fuel economy and better performance," she says. "There are no negatives except it costs a little more."
Whichever oil you choose, Schappell says, be consistent. Don't mix synthetics and blends, which can cause problems.
Gas also matters: Different cars benefit from different types, so check your manual. "For a Honda which runs really hot because of the compression, if it says run premium, then run premium," Fix says. "But if it says there's no benefit from premium gas," you don't need it.
Find the right shop
Ask friends and neighbors and search online for reviews of repair shops. Once you've chosen one, get to know the staff and ask questions.
Sticking with your car's dealer can be a safe choice, but that can get pricey.
The cost of repairs can vary widely depending on the car. Parts for some vehicles, including exotic cars and some German models, can be hard to get, driving up their cost. That can be a reason to trade in a car just before the 100,000-mile threshold.
At 100,000 miles, Fix says, "it is out of warranty and you've got to consider that."
When replacing parts, there are ways to save money: "A quick oil-change place will charge you $50 for an $18 air filter," she says, because you're paying for labor. But an auto-parts store will charge you only the $18 price tag, she says, and "you can buy it and say, 'I don't know how to put this on.' They'll do it as a courtesy."
The type of miles matter
Highway driving puts less stress on a car than tooling around locally. It requires less braking and acceleration.
With local driving, "if you sit in rush hour traffic, tow a trailer, idle outside a school, drive on dusty roads, that's considered severe duty," Fix says.