How to Increase the Fuel Mileage on Cars

by Contributing Writer; Updated June 12, 2017

You don't need to be a physicist to understand how strong wind resistance can be while you're driving at high speeds. This isn't a problem if you drive an aerodynamic car, but if you're driving a truck with a Towing Trailer car attached, you're losing gas efficiency. The issue is the Towing Trailer car large, flat surface area. Since the wind cannot get around the Towing Trailer car easily, your truck will have to utilize more power and fuel to keep moving. Wind Towing Trailer car help decrease wind resistance by redirecting Towing Trailer car flow over the Towing Trailer car. This, in turn, reduces the amount of power necessary to move the Towing Trailer car and increases fuel efficiency.

Under The Hood:

 How to Increase the Fuel Mileage on a Jeep Grand Cherokee

Replace the spark plugs with higher-performance models by turning each one in a counter-clockwise direction and securing a new one into the opening. Two things matter the most on a spark plug: heat range and the gap distance of the tip. The Grand Cherokee can use a plug with a heat range of four, but using a hotter or colder plug can change the performance of the motor. For towing, or high-torque applications, a hotter plug will work best. For highway driving, a colder plug range of three will be more efficient. Be sure to "gap" the plug, if using a one-node design, to about .060 mm. If using multi-node, or even quad-tipped plugs, then gapping is not necessary.

Install a clean air filter by opening the air box in the front of the engine and replacing the white paper element inside. A cleaner air filter can increase the air flow to the motor and require less gasoline to burn. An aftermarket air snorkel kit can maximize this air flow, but can cause issues with the computer systems that use an MAF sensor.

Clean the fuel injectors, intake manifold and throttle plate with a commercial spray cleaner. Take the air hose off of the intake manifold by turning the hand-screw on the unit in a counter-clockwise direction. With the engine off, spray a liberal amount of cleaner onto all metallic parts in the air opening. Let it sit for a few minutes, then crank the truck up and run it for several minutes. Shut the truck off and repeat the procedure until the metal is shiny and clean.

Clean the MAF or MAP sensor, if equipped, by removing the sensor from the air hose near the air filter box. Most types are an in-line hose unit that will couple with the air hose with a hose clamp. Turning this hose clamp counter-clockwise will release the hose and MAF sensor unit. Some later models of 4.0-liter straight-six cylinder engines and most 5.7-liter V-8 motors will have a MAF or MAP sensor that meters fuel by constantly testing the incoming air oxygen content. These sensitive sensors can be cleaned with special cleaning spray that does not leave residue. Spray the sensor until it is clean, but do not touch it. Replace it and secure the air hoses.

Add BG-44K to the gasoline tank during a fill-up. This unique cleaner will break up carbon deposits in places the spray cannot reach. It will also clean parts of the fuel system chemically.

Items you will need

  • High-quality spark plugs

  • 8mm (or thicker) ignition wire set

  • Fuel-injector cleaner spray (or carburetor spray)

  • Air filter

  • MAF or MAP sensor cleaner

  • BG-44K gasoline additive

 How to Improve Gas Mileage on a Honda Ridgeline

Drive at constant, moderate speeds. Gas mileage is lower in the city because accelerating burns up much more fuel than traveling at a constant speed. When you are driving in traffic or on the highway, try to moderate your speed so you are not accelerating and slowing down unnecessarily. Use the cruise control feature on the highway when convenient. Gas mileage also decreases rapidly after you reach 60 miles per hour, according to

Keep your vehicle properly maintained. Get regular tune-ups. With the Ridgeline's V6 250-horsepower engine, replacing the spark plugs, air filter and fuel filter, according to Honda's recommended maintenance schedule, is important. Also, make sure you are using the proper grade of motor oil and gasoline. Keep your tires properly inflated according to the recommended psi level in your owner's manual. Under-inflated tires will cause more drag on your Ridgeline, lowering its fuel efficiency.

Keep your truck light. Heavier vehicles require more gas to move. Remove any unnecessary items from your trunk or your rear seats. If you do not even use the rear seating section, you might even want to consider removing it as well. The rear seats can easily be taken out by removing the six 14 mm bolts holding the seats and center seat belt in place.

Limit air conditioner use. Using the air conditioner will demand more energy from your truck's engine. Try to use it sparingly at a temperature control setting that is not going to cause it to be on constantly. Conversely, if you are driving around with all your windows open, you will be greatly increasing drag on your truck. Try to find a balance between the two options.

Install a cold air intake system. If changing your driving and maintenance habits aren't enough for you, consider adding an air intake system to your Ridgeline. Such a system replaces your stock intake tube with a wider pipe, filling your combustion chamber with more oxygen for igniting fuel with a more efficient mixture.

Consider upgrading to a 2011 model. Honda has been listening to Ridgeline drivers complain about the low fuel efficiency of the truck. The company plans to focus on improving the truck's aerodynamics and powertrain to make it more fuel-efficient for its 2011 model. If trading in and up is an option for you, consider it.

 How to Improve Gas Mileage on a PT Cruiser

Cruising Efficiently

If you do not already own a Cruiser, consider opting for one with a manual transmission, which goes slightly more miles per gallon. The turbo automatic fares the poorest among the Cruiser models.

Follow the factory recommendations for service and maintenance. Keeping the Cruiser running well keeps its engine performing optimally, and ensures the most efficient fuel consumption possible.

Use 87 octane fuel for standard Cruisers and 92 octane for Turbo Cruisers.

Keep tires properly inflated: 34PSI for stock, 38PSI for turbo.

Use air conditioning sparingly; when in use, opt away from "max." The engine runs the air-conditioning compressor, so the more you use the AC, the more the engine is working, and the more fuel it wastes.

Check the car's coolant levels regularly. An engine that is overheating is working too hard and not making the most efficient use of its fuel.

Change the oil every 3,000 miles to ensure a properly running engine.

Replace air filters every 15,000 miles. Clogged air filters severely limit the ability of your engine to work at its optimum level.

Inspect spark plugs at least every 15,000 miles to ensure that they are working optimally.

Drive sensibly and at moderate speeds. The four-cylinder Cruiser is designed for optimum fuel efficiency when driven at steady speeds below 60 miles per hour. Avoid stops and starts or sudden acceleration.

Keep unneeded weight out of the vehicle. The more you pile into the Cruiser, the poorer the MPG.

Tow only when you need to. While the Cruiser is capable of towing, fuel consumption is much higher while doing so.

 How to Improve the Gas Mileage on a Hummer H3

Use the smallest tires possible. The engine has to work harder to rotate large tires.

Remove excess weight from the trunk. The H3 weighs 3 tons, and excess weight only makes the engine work harder. Remove the roof rack from your H3 if you are not using it.

Change the oil every 3,000 miles with the correct grade of oil. While you are getting an oil change, make sure the mechanic checks the air filter, tops off all fluids and checks the tire pressure. A dirty air filter and low tire pressure reduce fuel economy. Check your tire pressure every month.

Change your driving style. Do not floor the gas pedal to accelerate quickly or drive at high speeds. Set the cruise control at the speed limit on the freeway. Rather than breaking hard for an upcoming stop, anticipate the stop and let up on the gas pedal in advance. Altering your driving style is the best way to improve fuel economy.

Avoid driving during rush hour. Idling in traffic for more than a few minutes burns gas and reduces your fuel economy. Turn off your H3 if you are waiting in a parking lot, and don't let the car idle to warm up in the morning. If the temperature is under 30 degrees F, it takes an H3 less than a minute to warm up.

 How to Improve the Gas Mileage in a Honda Civic

Better Mileage

Replace worn tires with the original tire size used by Honda. Avoid bigger tires, as Perronne recommends. Pay a mechanic for a wheel alignment because that operation requires computerized heavy equipment.

Make sure your tires are properly inflated, and don't use metal rims or hubcaps because they add weight to the car. Use plastic wheel covers.

Remove all extra weight in the car, including any tool sets, computers and equipment you are keeping in the trunk. Avoid running the air conditioning.

Replace the spark plugs, wires, air filter, fuel filter, oxygen sensor, oil and oil filter as needed. Add an oil additive to improve motor compression for older cars. Use only oil recommended by Honda and maintain the oil at the proper level. Avoid overfilling the oil because that fouls the plugs and reduces mileage.

Start gradually from red lights or stop signs and accelerate slowly but safely, always watching other traffic. Avoid touching the brake while driving unless absolutely necessary. Avoid stop-and-go driving and take the highway when possible because highway driving improves gas mileage.

Drive at 55 mph on the highway as long as it's legal. Maintain the minimum legal speed on the freeway, usually 10 mph under the posted speed limit. Use gravity to your advantage as you drive. Avoid accelerating uphill, let the car accelerate as you move downhill and let your momentum carry you past the base of the hill and partly up the next one.

Use carburetor cleaner to clean the carburetor inside the air filter housing while letting the motor idle. Remove all gunk from your carburetor for a significant increase in mileage. Use fuel injector cleaner in the tank.

Adjust your idle to original levels, and make sure your cooling and charging systems are functioning properly. Ensure that the vacuum level on the emissions control equipment is correct because the vacuum affects fuel flow. Ensure that the fuel pump is working and that the fuel pressure is correct. Maintain transmission fluid at the proper level.

Items you will need

  • Toolkit

  • Car manual

  • Fluids and parts

 How to Improve Gas Mileage on a V8 Sierra

Go to a mechanic for scheduled maintenance. Click on the link "GMC Maintenance Schedule" under "References" at the bottom of this page and input your year and model of Sierra. This will show you what you need to have inspected at certain mileage intervals.

Get regular oil changes every 3,000 miles. Changing the oil is one of the easiest ways to maintain the health of your engine. Oil becomes thick over time, and the engine needs to use more power to move the oil through the motor, which reduces fuel economy.

Consider installing Eibach Springs on your Sierra. Eibach Springs reduce drag and improve all around performance. They have been shown to improve fuel economy, especially on pick up trucks like the Sierra. Click on the link "Eibach Springs" under "References" for more information.

Change your driving style. Do not accelerate quickly from a stop. Set your cruise control on a speed no higher than 65 to 70 on the highway. Driving at high speeds reduces fuel economy. If you anticipate a stop ahead, let up on the gas and glide to a stop rather than accelerating and having to slam on the brakes. The Sierra is a heavy vehicle and takes a great deal of power to propel. Altering your driving style is one of the best ways to improve your miles per gallon.

Remove excess weight from the truck and tow as little as possible. Although the Sierra is made for hauling and towing, these activities use extra power, causing the Sierra to get fewer than its estimated miles per gallon.

Items you will need

  • Oil change

  • Eibach Springs

 How to Improve Mileage With a Towing Trailer Air Deflector

Position the air deflector as far back on the roof of your truck as possible. You want to shorten the distance between the deflector and the trailer to ensure the trajectory of the wind flows over the trailer.

Center the air deflector so it is positioned in the middle of your truck's roof. A precise middle position will deflect the maximum amount of air that your trailer would otherwise come into contact with. Positioning the air deflector too far to the left or right will leave parts of your trailer exposed to straight-on wind resistance.

Firmly plant down the suction cups on the bottom of the deflector base to the roof of your truck. Use a damp rag and rub the inside of the suction cups if you're having trouble creating enough suction. Give the base a moderate tug or push to make sure it's secured.

Attach the mounting hook to the weather stripping above the driver and passenger-side windows. Feed the nylon straps on the air deflector base through the mounting hooks and lock them in place. These nylon straps will prevent the air deflector from dismounting your car if the suction cups fail. As such, make sure the straps are locked in position.

Adjust the angle of the air deflector if the model you purchased has this feature. Increase the angle of the air deflector for tall trailers. You only need to raise the air deflector high enough to divert air flow over the trailer.

Items you will need

  • Damp rag

  • Drill

  • Mounting hook

  • Nylon strap

  • Towing air deflector with suction cup base

 How to Improve Fuel Mileage for a Subaru Outback

Improving Gas Mileage

Change your oil and oil filter. Use oil additive to fight low compression and increase power and gas mileage.

Change your fuel filter and air filter. Check your fuel pressure and check the fuel pump if pressure is low. Maintain proper fuel pressure.

Use fuel cleaner in the tank. Remove the air canister top, crank the car and spray the carburetor with carburetor cleaner. Remove all carbon buildup to significantly improve fuel economy.

Check your battery with a voltmeter. Disconnect it and change your spark plugs and spark plug wires. Re-connect the battery after you've replaced the spark plugs.

Have your clutch checked. Replace the clutch when it's very worn and adjust the pedal to increase gas mileage.

Adjust your idle to the manufacturer-recommended levels.

Check your vacuum with a vacuum gauge and ensure that it is at the proper level. Add and tighten clamps on the hoses as necessary to prevent leaks. Maintain a good vacuum because it affects fuel flow.

Check all fluids, including motor oil, transmission oil, brake fluid, power steering fluid and radiator fluid. Maintain all fluids at proper levels.

Replace worn tires and have a professional align them. Keep the tires inflated at the proper level.

Throw out all extra weight. Get rid of specialty-item crossbars in Subaru wagons. Avoid carrying tools and equipment.

Adjust your driving habits. Avoid racing the engine and accelerate gradually. Take the freeway and avoid stop-and-go traffic. Avoid using the air conditioning because it lowers gas mileage.

Drive at a steady top speed of 55 miles per hour on the freeway, and take flat routes rather than hilly courses. Accelerate naturally going down hills and hold your speed steady going up hills. Use the highest gear while on the freeway. Avoid excessive braking, and stay safely away from the car in front of you so that you'll have plenty of time to slow down without braking.

Items you will need

  • Tool kit

  • Subaru Outback manual

  • Air Filter

  • Oil, oil additive, and oil filter

  • Fuel filter

  • Spark plugs and wires

  • Fluids - brake, radiator, and power steering

  • Carburetor cleaner

  • Fuel cleaner

  • Fuel injector cleaner

  • Voltmeter

  • Fuel pressure gauge

 How to Improve Gas Mileage in a Ford Mustang

Replace the air filter with a high performance filter. Stock air filters generally err on the side of caution rather than efficiency. An engine needs oxygen to operate, and the oxygen which enters the engine must first pass through the air filter. Stock air filters are generally more restrictive than aftermarket units, meaning that the engine must use more energy to draw air through a stock air filter than an aftermarket one. Many aftermarket air filters are available that filter the air just as efficiently as, if not better than, stock units but do not require the engine to work as hard to draw air through the filter. Switching to a quality air filter will thereby result in an increase in fuel mileage.

Upgrade the exhaust system. Most Mustangs were equipped with very restrictive exhaust systems. The engine must pass the exhaust fumes out of the engine and through the exhaust system. Many Mustangs, even those equipped with V-8s, were assembled with a single exhaust pipe. Use of a single exhaust pipe severely restricts the engines ability to dispense with the exhaust gases. By converting the single pipe exhaust system to a duel exhaust, the engine will not have to work as hard, thereby resulting in an increase in power and fuel mileage.

Upgrade the ignition system to an aftermarket electrical ignition system. The ignition system is responsible for igniting the air/fuel mixture that the engine burns. The stock ignition system can be grossly inadequate to efficiently ignite this mixture. This is particularly problematic for the older Mustangs which used a mechanical point system in the distributors and weak ignition coils. Installing a quality aftermarket electrical ignition system will increase the efficiency of the engine, resulting in better gas mileage.

Always change the oil every 3,000 miles. Old oil, or a low oil level, actually reduces the efficiency of an engine. This loss in efficiency reduces the miles per gallon of gasoline the engine must consume to reach a given point. Replacing the oil every 3,000 miles will help the engine to operate smoothly, thereby improving the Mustang's gas mileage.

About the Author

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