Driving More Efficiently: Get The Best Gas Mileage On Your Car And Truck

Following these tips may save you money on gas and help the environment too

Driving More Efficiently: Get The Best Gas Mileage On Your Car And Truck
Image: NCCC
July 3, 2018

Looking for ways to save money on fuel costs? These days, it seems that everyone is trying to stretch a gallon of gasoline a few extra miles.

There are a number of ways you can get better fuel economy. Not all vehicles are created equally and some vehicles will reap better fuel mileage than others, but these things can help you get the most out of your tank and get into the passing lane to save money.

Maintenance Is Very Important

Properly Inflated Tires

In vehicles we tested, a tire pressure drop of five Pounds Per Square Inch (PSI) resulted in an average decrease in fuel economy of 2.4 Miles Per Gallon (MPG). Check tire pressures weekly and only when the vehicle has not been moved for at least eight hours. You are measuring cold tire pressure; if you measure tire pressure after the car has been recently driven, you can get inaccurate tire pressure readings.

Over-Inflated Tires

Over-inflating tires past the manufacturer's recommended PSI does NOT significantly increase fuel economy. It makes the ride harsher, your tires wear faster, and increases the likelihood of a blow out. The manufacturer has set the recommended tire pressure to account for the best fuel economy, safety, and proper handling.

Don't Put Off Maintenance and Repairs

Replace components as recommended in your owner's manual. Bad spark plugs, air filters, oxygen sensors and the like will make your vehicle run much less efficiently. If the computer is getting a bad reading from one area of the vehicle, it will be giving wrong instructions to the rest of the vehicle. Have your vehicle repaired immediately if any service lights illuminate on your dash. These lights indicate a failure in one of the components relating to fuel and emissions. Under the Federal Emissions Warranty, some repairs to emissions components are free for the first eight years or 80,000 miles. If your vehicle has mechanical problems, you could be decreasing your fuel economy by as much as 50%, not to mention harming the environment.

Cars Are Controlled By Software, So Updates Might Be Available

Ask your dealer for an engine computer software upgrade, which is often free if your vehicle has less than 80,000 miles. The software may be updated to provide more efficient operation, not to mention fix other problems. While you're there, the dealer can also update the other modules in the vehicle, but it might cost you if you are not within warranty.

Synthetic Oil Costs More, But It's Better

Use fully synthetic motor oil in your vehicle. While more expensive, this oil is made from polymers, not crude oil, and results in superior performance, no sludge, better horsepower, and up to three percent better fuel economy. It also lasts longer than conventional oils, so you can stretch out your oil changes. Some car manufacturers using synthetic oils recommend service intervals of 15,000 miles or longer. Don't buy into the 3,000 mile oil change myth and change your oil based upon manufacturer recommendations.

Lose Some Weight

Remember that the weight of a vehicle is not limited to the vehicle itself. The items you put into it also have an effect. Are you driving around with a 200-pound toolbox? Do you still have sandbags in your trunk from last winter? For every 100 extra pounds, fuel economy drops by about three percent.

Don't Be A Drag

Aerodynamic drag can kill fuel economy. Reduce wind resistance by removing luggage racks and like items from the outside of your vehicle. If comfortable, keep your windows up at highway speeds to reduce drag even more.

Driving Habits

Higher Octane Fuel Doesn't Always Mean Better Economy

Use the cheapest type of fuel possible. If your vehicle needs regular unleaded, don't put premium in the tank. Modern vehicles are computer-controlled and automatically adjust for variations in fuel. A higher octane fuel doesn't always give more power or better performance. But exercise caution when deciding on using a flex fuel. Flex fuel, or E85, contains a much higher concentration of ethanol than conventional fuel, but not all vehicles can handle it. Only use this fuel if your vehicle is specifically designed for it or you risk engine damage.

Don't Warm Up Your Car on cold days

Don't warm up your car. Instead, get in and drive off normally. Your car will heat up faster and you won't waste gasoline sitting there. According to vehicle manufacturers, the stress an engine experiences from a cold startup followed by ten minutes of idling is equal to 80 miles or more of highway driving. In the old days of carburettors, you had to warm the car up in order to have the car function properly. You don't have to do that with the cars of today.

Slow Down to Save Gas and Avoid Speeding Tickets

The faster you drive, the more gasoline you use. Most cars get the best efficiency between 45mph to 50mph. For every 1mph over 55mph you drive, you can expect to lose and average of between 1% and 2% of your fuel economy and even more if you drive a boxy car. Fuel economy drops significantly after 60mph. Always drive safely.

The Pickup Truck Tailgate Myth

If you own a pickup truck, leave the tailgate up! Keeping your tailgate down while driving reduces your fuel economy by increasing aerodynamic drag. When the tailgate is up, a bubble of air called a vortex is created in the bed. That's why you can carry on a conversation when riding in the back of a pickup truck. This vortex pushes the air coming over the cab higher, causing it to flow over the top of the tailgate. When the tailgate is left down, the vortex collapses and the air rushing over the cab pushes down on the tailgate, increasing stress on the bed and creating additional drag.

Use Overdrive, Automatic Gears or Eco Mode When Possible

Vehicles vary a lot. Some automatic transmissions have a 'Drive' gear and an 'Overdrive' gear, which was originally intended for highway driving. Use overdrive when possible, as it allows the vehicle to operate more efficiently. In newer vehicles, overdrive has been replaced by 'Eco mode' buttons and settings. Eco mode reduces the 'peppiness' of you car ever so slightly, but it increases your fuel economy significantly. If you are in Eco mode and need sudden acceleration, the car's computer will detect how quickly you push the accelerator and will temporarily disable Eco mode. If you have an automatic transmission that also has manual shifting, don't use the manual shift. It isn't calibrated for peak fuel economy, even if it does make the car more fun to drive.

Jackrabbit Starts Can Really Hurt Fuel Economy

You may not have heard the term, but you've definitely seen a jackrabbit start as you watch someone at the red light next to you accelerate rapidly only to stop at the next red light. Sudden acceleration not only wastes a lot of fuel, it puts unnecessary stress, wear and tear on the car. You don't necessarily have to drive like grandma drove, but slower starts are definitely better. And if you need any more convincing, look at how long grandma's car lasted! Besides, these types of starts can use 40% more fuel that a slow start. More than half of the fuel you use to power your car goes to accelerating, so less accelerating will save fuel.

Plan Your Day To Avoid Heavy Traffic

Avoid rush hour traffic if you can. As you're sitting in traffic, you're getting zero MPG. Do you have a flexible employer? You might be able to go to work an hour earlier/later and leave work an hour earlier/later to avoid the heaviest traffic. If you can't change your schedule with your employer, consider getting to work a little early or leaving a little late anyway. Quite often a 20-30 minute adjustment to your schedule can make significant improvements to your drive (and sanity). You should also consider alternate routes. Sometimes the shortest route isn't the most fuel efficient. A route that is five miles longer might be all highway with no traffic lights, which could mean no idling or frequent acceleration when compared to the shorter route. As a last resort, you can consider turning your car off if you are sitting in traffic. But remember that you'll be using your battery power only and you'll need to be in Park or Neutral in order to restart the car. If your battery gets too low, you might have trouble restarting your car. But you should be good for a few short sessions, especially if your battery is newer and in good shape.

Park In The First Available, Furthest Parking Spot

We know. It sounds silly. But think about the fuel you'll use when circling the parking lot for a space close to the door. If you park in one of the first available spaces, you'll be able to turn the car off sooner, you'll be closer to the exit, you'll get a little exercise, and you won't run as many risks of getting dents and dings from other cars.

Group Your Trips Together To Keep Your Driving Time to a Minimum

Some of us don't like to plan, but it can make a difference. Instead of doing trips as needed, try to plan them out ahead of time and group them together. Are you going to your parents' house this weekend? If the grocery store or mall is on the way and you need to make a stop, see if you can hold out until the weekend and do your shopping at the same time. This can become habit with some practice. While it doesn't really better your fuel economy, it definitely helps you to use less fuel. Many online map websites and apps give you the option to set multiple destinations, optimizing your drive between them. Consider entering some of your regular trips into one of these maps to see if you can consolidate some of your driving. A few miles here and there can add up.

Keep the Inside of the Car Cool When Parked in the Summer

Some of us chuckle when we see others trying to get the parking spot with the most shade. But if you use your air conditioning, and nearly everyone in North Carolina does, you can use less fuel by cooling down a slightly cooler car. Everything in your car ultimately gets its power from gasoline, and that includes your air conditioner. The harder it has to work, the more fuel you use. If it only has to cool your car down from 90 degrees instead of 120 degrees, you'll use less fuel initially cooling the car. Don't have shade? You can reap a cooler interior (and a cooler looking car) by getting window tinting. Don't like the dark look? Clear tint that blocks only heat can be applied, cooling the inside of the car while leaving the visibility completely clear. You can also buy an inexpensive windshield shade or leave a window/sunroof cracked. But keep an eye on the weather! A sudden shower can leave you feeling a little wet!

Don't Turn the Air Conditioner On Right Away

Our first instinct in the summer heat is to turn the air conditioner on. But even when on at full power, it takes a little while for the air conditioner to get cool, especially as we mentioned above if the inside of the car is very hot. When you get in the car, put your windows down to quickly vent some of the heat. Some cars even have key fobs that can lower your windows for you before you get to the car. Even on a hot summer day, the air outside the car is cooler than the inside. Once you get driving, keep your air conditioner off for a few minutes but turn your blower fan to maximum to help cool the car before you turn the air conditioner on.

Turn the Air Conditioner Off In Cooler Weather

Using the air conditioner can decrease fuel economy between 15% and 35% depending upon your speed and the aerodynamics of your car. If it's cool and comfortable outside, consider just using the blower vents to let in some fresh air or open the windows. Even at highway speeds and with newer vehicle technology, having the windows down and the air conditioning off will almost always use less fuel than having the windows up and the air conditioning on.

Turn the Air Conditioner Off During Frequent or Heavy Acceleration

You already know that a car uses the most fuel during acceleration. An air conditioner robs most of its fuel during acceleration, so it's a double whammy. Turning it off momentarily if you are accelerating and then turning it back on can save fuel.

The Air Conditioner Is On When The Air Blows from the Defroster

The air conditioner turns on and subsequently uses more fuel any time the front defroster is turned on and the outside temperature is above a certain point, usually 37 - 41 degrees. So turn the air flow back to another setting once it's no longer needed on the windshield or the air conditioner will run needlessly.

When Shopping for a New Vehicle and Accessories

New Vehicles Typically Use Less Fuel, But Not Always

While newer vehicles typically use less fuel than the older model you currently drive, this might not always be the case. Certain vehicle options and features, such as four wheel drive or all wheel drive, can lower fuel economy. So if you're shopping around, don't always assume the new car will get better fuel economy until you see the specs.

Get A Car That Has Been On A Diet

Just like the weight of items you put into the car, the weight of the car matters. Four wheel drive and all wheel drive adds weight to the car, which lowers fuel economy. Smaller cars typically get better fuel economy than trucks and SUVs because of weight, both of the car itself and the size of the engine needed to move it.

More Power Typically Means Worse Fuel Economy

300 horsepower might sound awesome, but how often do you really need it? The more powerful the engine, the larger and heavier the engine will have to be. Nearly all performance modifications use more fuel, from larger engines to specialized computer tuning. Manufacturers have been working for a while now to transition from power-based advertising to fuel efficiency, so you'll typically find less vehicles that have been tuned with extra power.

Turbochargers vs Superchargers

More power doesn't always mean less fuel economy. If designed correctly, a manufacturer can add a turbocharger to a car while simultaneously shrinking the size of the engine, resulting in the same amount of power but lower weight and better fuel economy. We're seeing more of this as vehicle manufacturers work to improve fuel efficiency but keep up with the power demands of the average driver. Turbochargers can increase the fuel economy of the vehicle when it is added as part of the original design. They run from exhaust gases and use energy that would ordinarily go out the exhaust pipe. Superchargers, on the other hand, are driven by the engine, which means they are always running and always using engine power, even at idle.

Electric Power Steering vs Conventional

Power steering was a great invention, but it runs from a mechanical pump that is driven from a belt connected to the engine. That basically means that the engine is always powering the pump. Electric power steering is driven only by electricity, which means overall the system is lighter and isn't putting constant drag on the engine. This translates to a fuel economy increase of about 1 MPG. It's also more responsive than conventional power steering, which is most noticeable in parking lot maneuvers and at certain highway speeds. They also have no fluid, which means they don't leak, are easier to replace and service, and more reliable. But not all cars have this technology as car makers have been slow to adopt it and drivers slow to embrace it. If you are doing a custom build, opt for this technology. Sometimes it is only reserved for more pricey editions of a vehicle line, such as the limited models.

Smaller Tires are Better For Fuel Economy

Smaller tires weigh less than large tires and typically have a lower rolling resistance, which in turn burns less fuel. Bigger and wider tires grip more of the road, but use more fuel. You'll have to evaluate the trade offs when deciding how big you want your tires and wheels to be.

Continuously Variable Transmissions (CVTs) and Higher Gear Ratio Automatic Transmissions

The more gears a transmission has, the better the fuel economy and quieter the ride. In the 1990s, you'd be hard-pressed to find an automatic transmission with more than four gears or 'speeds.' During those days, a manual transmission was the most fuel efficient way to go. But times have changed. Transmissions may have gotten bigger, but manufacturers have crammed more gears into them that achieve a much better ride and much more fuel economy. Transmissions with six gears are extremely common today, with many even offering eight, nine or even ten gears! As you drive faster, the transmission shifts to a higher gear, uses less fuel, and gets quieter. Also making a surge in popularity are Continuously Variable Transmissions (CVTs), which as their name implies continuously vary the gear ratio of the transmission to an almost unlimited number of gears, which always give the optimum fuel economy and power. But they are limited with what they can tolerate mechanically and don't do well in vehicles with a lot of power. CVTs get about 3 MPG better fuel economy than automatic transmission with four gears, and about 1.5 MPG better fuel economy than manual transmissions.