General Lab Information

Reducing Air Pollution and Optimizing Mileage

Aside from ridesharing, there are many practical ways each of us can help to reduce pollution and optimize gas mileage from our cars.

Driving Tips

Drive at a Steady Pace - Fuel efficiency increases when you drive at an even speed. You can also improve your gas mileage by avoiding fast starts and quick stops and by using cruise control during highway driving.

Drive at Moderate Speeds - Most cars operate most efficiently between 35 and 45 miles per hour. Operating your car at lower and higher speeds reduces fuel efficiency. For highway driving, gas mileage can increase by as much as 15 percent if you drive at 55 miles per hour rather than 65 miles per hour.

Combine Your Trips - By combining your errands into one trip, you get more things done faster with less driving, less gas, and less pollution. Starting a car after it has been sitting for more than an hour creates up to five times more pollution than when the engine is warm.

Avoid Unnecessary Idling - Contrary to popular belief, your car uses more fuel when your engine idles for 30 or more seconds than when you turn off and restart your engine. To improve your fuel economy, try reducing engine warm-up time in the winter and turn your engine off in traffic jams. Idling for long periods in cold weather can lead to excessive engine wear.

Get Fuel When it's Cool - Postpone refueling your vehicle until the cooler evening hours. Evaporative losses of gasoline from refueling are less when the temperature is lower.

Don't Top Off the Tank - It releases gasoline fumes into the air and cancels the benefits of the pump's anti-pollution devices. Stop short of a full tank, it's safer and reduces pollution.

Avoid Carrying Unneeded Items in the Trunk - Extra weight decreases gas mileage. Also, reduce drag by placing items inside the car or trunk rather than on roof racks.

Maintenance Tips

Keep Tires Properly Inflated and Wheels Aligned - Proper tire inflation and wheel alignment prevents excessive drag and can improve your fuel economy by up to one mile per gallon. Properly inflated tires are safer and last longer.

Get Regular Tune-ups and Maintenance Checks - A tune-up can improve your car's performance and gas mileage. Poor starting, rough idling and lower gas mileage may be signals that your spark plugs are worn and need to be replaced. Repairing a faulty oxygen sensor can improve your mileage by as much as 40 percent. Also, follow the manufacturer's guidelines for replacing motor oil and air filters.

sae 5w-30

Use an Energy Conserving (EC) Grade of Motor Oil - You can improve your gas mileage by using the manufacturer's recommended grade of motor oil. For example, using 10W-30 motor oil in an engine designed to use 5W-30 can lower your gas mileage by 1-2 percent. Using 5W-30 in an engine designed for 5W-20 can lower your gas mileage by 1-1.5 percent. Also, look for motor oil that says "Energy Conserving" on the API performance symbol to be sure it contains friction-reducing additives.

Use Your Air Conditioner Sparingly - Running the air conditioner places added drag on your car's engine that can reduce gas mileage by up to 20 percent in city driving. Try rolling down the windows on those not-so-hot days or when you're stuck in traffic.

Check & Replace Air Filters Regularly - Replacing a clogged air filter can improve your car's gas mileage by as much as 10 percent. Your car's air filter keeps impurities from damaging the inside of your engine. Not only will replacing a dirty air filter save gas, it will protect your engine.

Know Your Car - Check the tailpipe for signs that your car may be running inefficiently. Black smoke means there is too much gas in the air/fuel mixture and the fuel injection system should be checked. Blue smoke means the engine is burning oil and excess hydrocarbons are being released. Pay attention to flashing dashboard lights that warn of engine problems. A sudden drop in gas mileage may signal engine troubles and higher vehicle emissions. Get your vehicle to a skilled automotive technician for repairs when you notice any of these problem indicators.