How to prep your car for a road trip

Tire pressure, oil changes and a few secrets make for an easy trip.

Brian Cooley Editor at Large
Brian Cooley is CNET's Editor at large and has been with the brand since 1995. He currently focuses on electrification of vehicles but also follows the big trends in smart home, digital healthcare, 5G, the future of food, and augmented & virtual realities. Cooley is a sought after presenter by brands and their agencies when they want to understand how consumers react to new technologies. He has been a regular featured speaker at CES, Cannes Lions, Advertising Week and The PHM HealthFront™. He was born and raised in Silicon Valley when Apple's campus was mostly apricots.
Expertise Automotive technology, smart home, digital health. Credentials
  • 5G Technician, ETA International
Brian Cooley
4 min read

When you're prepping your car for a road trip, summer or otherwise, there are important things to check as well as some old steps you can skip.

Here's how to prep for a trip so that your car won't become the center of your attention, which is seldom good.

We've arranged these tips in two groups: Things you can do and things you might want to have done at a shop.

What You Can Do

  • Diagnostic codes. The OBD-II port in your 1996 or later car carries codes that can tell you what trouble is lurking in the machine. The newer the car, the more the codes will tell you. Antuan Goodwin did a good overview of OBD-II devices
  • Tire tread. Shove George Washington into the tread via an upside down quarter. The top of his head should be at least somewhat obscured to indicate that a reasonable amount of tread is left. You can also look at the tire wear bars that run across the face of the tire. If they are flush with the tread, you need new tires. 
  • wear-bars

    If the horizontal wear bars are flush with the adjacent tread, you need new tires.

  • Tire pressure. Use a good quality gauge, not the one that pops out of the inflator everyone beats on at the gas station. Look for a label inside your car door or gas filler door to find the correct pressure numbers and know that those are the figures for a cold tire.   
  • Oil level. This is key. You want to have a full level of motor oil before you start a trip, even if its not the freshest. Here, quantity matters more than quality, at least in the short term. A car that runs out of oil on the road will not only strand you for the time being, but also may never come back to life.
  • Washer fluid. Get a bottle of concentrate, not one of those huge jugs of premixed stuff. Pour a little in your washer tank, then top it up with plain water per the ratio on the bottle of concentrate. 
  • Light bulbs . No part of a modern car is more like a snap-fit model kit than lights. You'll need few if any tools to replace bad bulbs these days, though checking brake lamps remains tricky without a helper (a nearby reflective store window can help). And if you are going to be driving an unfamiliar car, know how the headlights work. A lot of people in strange cars think their headlights are on when just the daytime running lights are activated, leaving the back end of their car dark at night. 
  • Battery inspection. Nothing will stop you dead on your trip like a bad battery. Check its terminals for corrosion that prevent power from flowing out of it and charge from flowing into it. Neutralize and clean corrosion with baking soda, a little water and a toothbrush. Wipe everything clean, then put the terminals back on and seal with battery terminal spray.   
  • Gas prices. If you're a gas price geek, real-time price apps will help you find the cheapest gas along your route in real time. I'm always more concerned with convenience than price, so I don't have a price app to recommend.
  • Toll policies. Check tolling where you're going. If you don't how it works, you can get stung with some nasty fees as you blissfully blow through transponders.
  • Window policies. Google the window tint level and device mount policies in the state(s) you're driving to. You can get a primary or at least secondary citation for breaking these rules that surprise a lot of drivers. Not much you can do about tint, but mounting your phone where its legal is easy to comply with.

What You Might Do

  • Brake pads. Pull off each wheel (though the fronts matter most) to get a look at the brake calipers with the pads peeking though them. Measure pad thickness and compare to the minimum specified by your carmaker, which you can search Google to find factory service manual citations. Like with tires, brake pads have wear indicators that make a horrendous squeal when they're down to replacement thickness.
  • Oil change. It always feels good to start a long trip with fresh oil and filter so that you know the long miles ahead aren't taking time off your car's life on the back end. 
  • Check your belt(s). Most car engines have a single, critical belt that runs the A/C, alternator to charge the battery, water pump to cool the engine and often the pump that makes the power steering work. That's a lot to go wrong if the belt breaks. Judge the belt by the mileage since it was replaced or new, cracks in the ribs on its underside or, most worrisome, small pieces missing from those ribs. 
  • Tune up. Not a lot to do here any more, modern cars have very long service intervals and far fewer of the common tune-up parts of yore. So this one is largely relegated to the long-term maintenance category, not short-term trip survival.
  • Battery test. This requires a battery tester to verify the battery's capacity, the charging system's health and how both perform under load. If you have any other work taking place at a shop, have them do this at that time.

Loading up

The last tip is to load your car inside as much as possible; Anything on the roof will reduce MPG, performance and possibly create wind noise and garage clearance issues. If you have to block the rear view mirror, you will probably be OK with the law as long as you have two functioning side view mirrors and use them. But know that your reactions in a sudden slow down will be impaired as the rear view is probably the first place you'll look.