The AAA-Chicago Motor Club keeps track of gas prices in the Chicago area. They report that the average price per gallon as of May 10 is $3.34. If you’re reading this at work just before leaving, you might want to think about the many ways you can save money on the way home with almost no effort at all. Here are some useful ways to save cash during your evening commute.

• Clean any junk out of your car before you go This seems trivial, but it really works, especially if there’s anything heavy in your car that doesn’t need to be there. I use to haul around computer monitors in my truck for several months and kept complaining about my car’s terrible gas mileage; removing the monitors one day did the trick.
• Drive the speed limit When I get on the interstate, I want to drive ten or fifteen miles per hour over the speed limit in order to get home a few minutes quicker. Every time I do this, though, I find myself filling up my tank a day or two quicker than I would if I just calmed down and drove the speed limit. Plus it saves me from the occasional speeding ticket. Keeps me from shelling out fines and keeps my insurance low.
• Watch the gas station prices I always keep my eyes peeled for changing gas prices on my evening commute. The differences between stations even on a short commute can add up to multiple dollars per fill-up. But don’t drive in when you see a good deal…
• Wait until the morning to buy gas if at all possible I always buy gas in the morning before work, never in the evening after work. Why? The morning temperature is cool, and the ground is cooler, meaning the gasoline in the underground tank is cooler and thus more dense. Since gasoline pumps in the United States measure by volume, that means you’ll get slightly more gas per gallon in the morning when the underground gas tank is cool than in the evening when the heat of the day has heated the gas. It will appear to you as a slight increase in miles per gallon.
• Leave the air conditioning off Unless the heat is unbearable, use the vents instead of the air conditioning. The vents are much, much more efficient than air conditioning and can reduce fuel costs by as much as 10%.
• As you approach a hill, punch the gas The only time when you’re better off speeding a bit (in terms of money) is if you’re approaching an incline; raise your speed before you start the incline and allow yourself to slow as you go up it, even dipping below the speed limit as you reach the top. This will cut down on gasoline use on the incline.
• Avoid rush hour, or take an alternate route Sitting and idling in rush hour traffic is an enormous waste of gas. You’re money ahead by taking an alternate route or simply waiting until the rush hour peak is over. Run some quick errands or get a bit of exercise before hitting the roads if you leave at the peak of rush hour.
• If you are stuck in traffic, turn your car off and on If you find yourself at a standstill, turn your car off if the wait will be longer than a minute. This is much more efficient than idling for that time. This was ingrained into me in my hometown, where one often had to cross a swing-span bridge; if it was open for a barge, it was far cheaper to kill the engine than to let it idle.
• On the open road, use cruise control set at the speed limit This ensures that you’ll use a minimal level of gasoline during the trip, as most cars are optimized to run most efficiently at approximately the highway speed limit.