Tips to improve your vehicle’s fuel economy

With the price of regular unleaded gasoline topping $4 a gallon, auto information websites TrueCar.com and AutomMD.com have come out with a simple guide to get more mileage from your vehicle.

Drive smoother: Be gentle with your gas pedal and your brakes. There’s no reason to speed up to a red light just to slam on the brakes. Aggressive driving will lower your gas mileage.

Slow down: Most vehicles get the best fuel efficiency at 45 to 55 miles per hour. Driving more than 60 mph can cut fuel efficiency 7% to 23%.

Reduce idling: Turn off your engine if you’re waiting for more than 20 seconds. Idling wastes more gas than turning off your engine and restarting it.

Use lower-grade fuel: Regular unleaded fuel won’t hurt most vehicles even if premium unleaded fuel is required. Unless your engine starts to knock or ping when using a lower-grade fuel, stick to regular.

Remove excess weight: An extra 100 pounds sitting in the trunk or back seat can reduce fuel economy as much as 2%.

Turn on the ventilator and turn off the air conditioning: The most efficient way to cool your car is with the air that comes in through your flow-through ventilator. Air conditioning or open windows (because of the drag) make your vehicle less fuel-efficient. Driving fast with the windows open can burn more fuel than the air conditioner.

Replace or tighten the gas cap: Fuel evaporates through gas caps with broken or weak seals, potentially reducing your car’s mileage 2%.

Keep the tires inflated: Tires that are improperly inflated have a higher rolling resistance, which reduces efficiency. Keeping tires at the proper pressure can improve gas mileage much as 3.3%.

Change the oil: Energy-conserving or synthetic motor oil can reduce engine friction, improving efficiency as much as 2%.

Replace the spark plugs: Misfiring spark plugs can reduce fuel efficiency as much as 30%.

jerry.hirsch@latimes.com