Dear Driving for Dollars,
I'm going to be taking a pretty substantial summer road trip in the Southwest U.S., and I know the basics about how to check out my car to make sure it's ready. I was wondering, though, is there anything different I need to think about because I'll be driving in exceptionally hot temperatures?
There are indeed a couple of things that can affect your car's performance during a summer road trip.
First, you probably know how important it is to check your tire pressure regularly, ideally monthly, to adjust for the natural loss of air in your tires over time. Of course, you'll want to do this just before your summer road trip. Keep in mind that, as temperatures increase, the pressure in your tires will increase as well -- about 1 pound per square inch, or PSI, for every 10 degrees Fahrenheit, according to the Tire Rack website.
So, if you are choosing to run your tires at a PSI that is on the higher end of the acceptable range listed in your owner's manual, your ride is going to get increasingly hard as you drive for long distances in hot temperatures. That may make for a harsher ride, especially on bumpy roads, that may not be as comfortable as when you have a slightly lower tire pressure.
Also, it's pretty standard practice to check your cooling and air-conditioning systems before a road trip, especially if it's been more than a year since they've been checked in your older car.
The cooling system already is exposed to very high temperatures from your engine, but when driving in hot climates, the system may struggle or even fail. It's cheap insurance to replace the radiator cap in case the rubber gasket is starting to fail before you depart. You also may want to carry some coolant with you and keep an eye on your engine temperature gauge as you drive for warning signs of problems with the cooling system.