Last week, the U.S. Energy Information Administration (EIA) rained on my summer road trip. It predicted the nationwide average price for a gallon of regular-grade gasoline will be $3.95 between April and September. Last summer, the national average price was $3.71. We lucky Midwesterners get a tiny price break: We'll be paying $3.90 (while those on the West Coast will face a shocking $4.20 per gallon).

Given the news, I wanted to understand what goes into gas prices and some steps drivers can take to save on fuel.

No surprise that crude oil -- a third of which comes from the tumultuous Middle East and North Africa -- makes up the bulk of the price, 72 percent. The work of refining the oil accounts for 12 percent of the price, taxes for 11 percent, and distribution and marketing gets the final 5.

A simple way to ensure a car runs efficiently is to maintain proper tire pressure. Deflated tires add drag. In general, a well-tuned car glides most smoothly. Fixing a big problem, such as a faulty oxygen sensor, can boost mileage by as much as 40 percent.

With cars, the number of bags you carry is limited only by the size of your trunk. Still, pack light. More weight requires more fuel.

To find the gas station in your area offering the lowest prices, log onto a website that tracks prices, such as www.gasbuddy.com.

I'll heed all that advice before I drive north this summer. But at the pump, I won't be contemplating what goes into the cost of fuel. I'll be daydreaming about the trip, shelling out not for gas but for the promise of sunny beach days, lazy nights and a week with family. As they say in the ads, priceless.

Send your questions or tips to travel editor Kerri Westenberg at travel@startribune.com, and follow her on twitter @kerriwestenberg.