Would you rather spend your money on gas or going out with friends? Gas or an extra espresso? New shoes or gas?

Improving your gas mileage not only reduces your carbon footprint, but it saves you money and (in same cases) means your car is running as it was intended to run. Here are some easy tips, courtesy of O'Reilly Auto Parts.

1) Drive smart: Keeping a constant speed while driving can get you 10-40 percent better gas mileage. Use cruise control while driving on the highway and avoid excessive braking and accelerating in city traffic when possible.

2) Limit A/C use: Use your vehicle’s air conditioner as little as possible (within reason). The compressor puts a greater load on the engine, which reduces fuel economy. Park in the shade whenever you can, use a sunshade in your windshield and leave windows cracked for ventilation.

3) Monitor tire pressure: If the air pressure in your tires is imbalanced or low, your vehicle will burn more gas than necessary. Consult your owner’s manual for the optimal level of inflation and check your tire pressure at regular intervals.

4) Remove extra weight: Leave non-essentials (especially heavy items) out of your vehicle, particularly if you drive a smaller vehicle. If you’re traveling and can’t avoid a heavy load, put your cargo in the trunk if possible.

5) Check air filter: As an air filter clogs with dirt and debris, airflow becomes restricted and causes a vehicle’s fuel management system to add more gasoline to the mix of fuel and air, lowering gas mileage. Changing a filter that’s clogged will restore the right ratio and help fuel economy.

6) Observe the speed limit: Driving the speed limit is not only safe and lawful, but traveling at higher speeds decreases fuel economy. Specifics vary from vehicle to vehicle, but fuel efficiency drops increasingly for every mile per hour exceeding 50 mph.

7) Keep idling to a minimum: When your vehicle is parked, turn off your engine to save fuel. Idling can use a quarter to a half gallon of gas per hour. Anything over 10 seconds’ worth of idling uses more fuel than shutting off and restarting your vehicle.

8) Change your oil regularly: Routine oil changes will improve the overall efficiency and gas mileage of your engine by preventing the breakdown of oil and the buildup of sludge that can happen over time.

9) Clean fuel system: A fuel injector/carburetor cleaner is a simple, affordable way to remove carbon deposits and moisture from the fuel system, improving the performance and efficiency of your engine.