MPG Calculator

Fuel economy has become the main mantra of car buying, due in part by rising gas prices as well as a greater awareness for the environment. Even if the thought of saving endangered species does not drive the need for reducing fossil fuel  consumption, certainly the price is a formidable driving force. So if you are a new car buyer or perhaps someone willing to maximize their miles per tank, knowing some tips and tricks certainly goes a long way over the years. The average lifetime of a car is around 11.4 years,¹ with an average mileage per year of 13,476,² and the math on that comes out to almost 154,000 miles over a car’s lifetime. As a result, saving even a gallon of fuel through careful driving can go a very long way into cost savings. Let’s take a closer look with this automobile fuel economy guide!

BENEFTIS FOR THE ENVIRONMENT:

Needless to say, every drop of fuel saved prevents noxious climate change .

ⁱ

BENEFITS FOR YOUR WALLET:

At the moment, the average price for gasoline and diesel in the United States is $3.327 per gallon and $3.886, respectively.⁶ This number is soon to increase with growing shortages and speculation-driven price spikes from widely publicized conflicts in oil producing countries. In Europe, the prices per gallon are approximately a whopping 2.3 times that of the United States.⁷ In fact, wherever you are apart from Venezuela (18 cents/gallon⁸) or the Middle East, saving on fuel can go a very long way in cutting costs. Just doubling your miles per gallon can save you half of your fuel costs, every time you fill up.

Cost: Low to Moderate

Depending on the kind of price saving you would like to engage in, options range from the standard tips and tricks of hypermiling  to replacing your car altogether. For example, if you own a Hummer H2 it is unlikely that fuel saving strategies would save you much in the long run given the shear size of the engine and weight. Upgrading to a newer generation car, however, will be well worth the money. A 1970’s car would at best give you 15 miles per gallon,⁹ while many of the new vehicles can grant someone a comfortable 30 miles per gallon or even higher. This would translate to instant savings every time you fill up. If your car, however, is not that old or a V10 Dodge Viper then this guide can work wonders to help you save on your miles.

Time and effort: Low to Moderate

The time needed to master hypermiling is actually quite low, but the effort can be moderate depending on how serious one is in implementing our strategies. For example, the effort required to drive carefully could be arduous but adhering even less strictly to the principles can still save you quite a lot of money at the pumps. If you already have a fuel efficient and eco-intelligent vehicle then perhaps the task is made even easier.

https://web.archive.org/web/20160404014416if_/http://www.youtube.com/embed/TfGFgXTpQW4 ⁱⁱ

Instructions

1) Become an Intelligent Consumer

• Evaluate Your Needs

Indeed, the first step to boosting fuel economy is to be empowered with the knowledge of fuel economy to prioritize your purchasing decisions. A GMC Sierra may seem to be a bargain at a starting MSRP of $26,075,¹⁰ but as a buyer you would want to evaluate whether towing or large trunk space is a necessity in your day to day life, especially since this kind of vehicle is rated at 16/23 MPG. If you are a person that requires the loading space, evaluate some other options on the market such as the smaller Toyota Talcoma which starts at almost half the price¹¹ ($18,125) and boasts an even better 21/25 MPG. Having 5 MPG higher in the city is outstanding, and you would save a fortune just based on the base price. Additionally, bear in mind that larger vehicles are not only much heavier but are much less aerodynamic than a small sedan. Therefore, an SUV with large ground clearance would be fuel inefficient due to the weight as well as the spacing between the ground and body that creates a good deal of aerodynamic drag. It is analogous to your vehicle trying to lift off like a plane due to the airflow underneath the car body, except the turbulent flow under the body creates a lot of friction. Don’t even think about adding huge wheels and tires, since the engine needs to generate much more torque to move a heavier wheel. The moral of the story is that unless you live in the wilderness or work as a construction contractor, it is not worth buying larger vehicles if smaller ones can offer the same practical benefit.

• Manage the Horses

Most of us as commuters never use the horsepower we are allured by in the ads. In fact, to maintain 60 miles per hour your car only needs to use 10 – 20 horsepower,¹² which is a miniscule percent of the total horsepower rating of your vehicle. Many of us would pay extra for the V6 or V8 model in the showroom, but the reality is that we would never use the power for daily commuting and activities. Not only is the extra powered engine practically useless, but a larger engine also consumes more fuel even if you are only using 50 horsepower or less to reach the speed limit.

• Choose Your Fuel

Nowadays, the availability of electric vehicles  offer a tantalizing array of options to consumers looking to buy a car. A fully electric car is the most ideal for long term fuel saving, but there is a price to pay, which is the price. The Nissan Leaf, which is a small subcompact starts at almost $29,000¹³ making it more expensive than the gargantuan GMC Sierra we were discussing earlier. On the flip side, the leaf attains a whopping 115 MPG combined, which is several times the fuel economy of even the most fuel efficient gasoline car on the U.S. market today. Additionally, most electric cars today have a low mileage range such that one would always be sitting on the edge of their seats anytime the battery meter begins falling. So while electric power vehicles are an undisputed winner in fuel economy, we would have to wait a few years until these vehicles become cheaper to buy and easier to drive without getting miniature panic attacks. A good alternative to electric vehicles are plug-in hybrids such as the Chevrolet Volt that come equipped with a back up gasoline engine, but the MSRP on this vehicle is still quite high at $26,685.¹⁴

There is one fuel, however, that has received much little press and popularity in the U.S. Diesel, synonymous with large trucks and military vehicles, has long been out of the public eye. There is, of course, a big reason why most large vehicles run on diesel—fuel economy. Diesel cars will tend to always beat their gasoline counterpart in matters of fuel economy. The Volkswagen Passat Diesel boasts 43 MPG highway, while its gasoline counterpart is 40 MPG.¹⁵ Although a small difference, these differences in MPG certainly add up over the years. Diesel engines are also much more reliable, and more clean burning these days compared to gasoline engines. Mercedes has taken advantage of this difference by offering their BlueTEC® line of diesel cars which are much more expensive based on a technology that has been saving fuel for decades.¹⁶ One can easily get an affordable diesel car within a similar price range to gasoline. Although the price of diesel is higher—around 50 cents per gallon more expensive than gasoline—primarily because diesel is not subsidized in the United States, the gain in fuel economy is well worth it. While electric cars do require a good deal of cost benefit analysis based on their base price, diesel cars are a no brainer for saving fuel while being sold at around the same price. In fact, diesel owners can go one step further and use biodiesel  in their engines that can cost 80 cents per gallon¹⁷ if one were to make it at home using very basic chemistry.

ⁱⁱⁱ

• Choose Your Transmission

While weight, fuel and engine size all make a huge difference in gas mileage, astonishingly, so does your transmission. One of the key aspects to fuel economy is your engine RPM (revolutions per minute), and therefore the RPM dial on your front dash is actually more important to your fuel economy than your speedometer. RPM measures the rotational speed of the crankshaft,¹⁸ and the bottom line is that the higher the RPM the more torque the engine is generating at that particular speed and to produce more torque your engine is consuming more fuel. As a rule of thumb the driver should minimize the RPM to save fuel, and incidentally the best way to minimize your average RPM is with a manual gearbox. An automatic gearbox does not change gears to optimize lower RPM, so one could be driving on the highway in 5th gear at a higher RPM when in fact shifting to the 6th gear would save much more fuel. Unfortunately, your gearbox does not know this and as a result manual control is best for saving fuel. If possible, buy a car with a semi-automatic gearbox that allows the driver to shift on his/her own accord. Fortunately, many cars coming out today are semi-automatic, and therefore when it comes to saving fuel the gear “M” is the way to go instead of “D”.

2) Plan Your Trips

After the issue of buying your car is in order, planning how to get there is also a significant benefit to saving fuel. Try to figure out all the places you intend ongoing during your driving trip, and accordingly plan to take a route that covers your destinations without needing to travel back and forth between places that could have been visited earlier or later. If you know your city well, try to avoid hills or congested roads that require a lot of stop and go type driving. Hills are particularly a menace for requiring a lot more engine power, and the worst part is that you would not be saving as much as you would expect on the way down.¹⁹

3) Reduce Your Loads

Weight makes a huge difference to fuel economy, and therefore leaving heavy groceries or consumer products in your car while driving around pushes your engine to work even harder. If you are a commuter, something as simple as removing your back seats in SUVs or vans can save a good amount of fuel. Additionally, saving money by choosing less upgrade options on your car can also go a long in boosting fuel economy. Satellite navigation and heated seats are some of the heaviest items to add as optional extras. All that being said, often the heaviest variables added to cars are in the human form. A co-benefit of being fuel savvy could be losing those extra holiday pounds at the gym, allowing you to save those dollars and avoiding those unnecessary drives to the doctor’s office.

4) Manage Your Fuel

Once again illustrating how important weight is to improving fuel economy, the best way to fill your tank is actually halfway. Gasoline weighs around 6 pounds per gallon.²⁰ Therefore, only filling half of a 10 gallon fuel tank saves you around 30 pounds in weight!

5) Properly Inflate Your Tires

Maintaining proper tire pressure can reduce fuel consumption by about 3 percent.²¹ Underinflated tires force the engine to work much harder due to the shape deformation of the tire with less air. Proper inflation insures a uniform tire shape that allows for a much smoother rolling motion on the road, so inflating to the manufacturer’s guidelines will be cash saving for you!

^iv

6) Change Your Air Filter

Dirty air filters can devoid the engine of clean air for combustion, and as a result a dirty air filter can reduce fuel economy by forcing the engine to work harder. Most air filters are fairly cheap, widely available and easy to install.

7) Change Your Oil

As engine oil is used over its regular cycle, it tends to become fairly viscous and the hampered flow rate pushes the engine to work even harder. Changing engine oil every 3000 miles and using synthetic oil, which lasts longer and is more environmentally friendly, can prevent a 2% loss in efficiency over time.²²

8) Clean Your Fuel System

Maintaining your fuel injectors and engine components over time, and preventing a buildup in fuel residue can go a long way in improving mileage. This process is best done every 6 months, and a variety of cheap and easy to use cleaners are available on the market.

9) Drive Carefully

Probably the most important piece of the puzzle—the way you drive—is what ultimately determines fuel economy on any given automobile.²³ Let’s look more closely at how you can change your driving technique to increase fuel efficiency.

• Accelerate Slowly and Watch Your Speed

Sudden accelerations at high RPM can seriously impact your fuel consumption, and overall such a maneuver is pointless when you might be saving a few seconds of on your journey time. Similarly, driving speed on the highway and side roads play a major role in fuel efficiency. The fuel efficiency numbers listed by the manufacturers are based on a highway driving speed of 55 miles per hour,²⁴ and anything above that kills fuel economy on the highway. From common experience, perhaps no one ever drives even close to this speed. People travelling at 70 miles per hour lose 17% of efficiency from 55 miles per hour, and those travelling at 80 miles per hour lose 28% of their efficiency. Therefore, driving at 80 miles per hour results in more than a quarter loss of fuel economy. So while the maniac travelling at 90 miles per hour may reach the destination faster, he/she is sure to incur more pit stops for fuel. In fact, if everyone were to obey the national speed limit of 55, we would save 1 billion barrels of oil a year.

• Manage Your RPM
• Avoid Braking

Minimizing the engine RPM is a surefire way of boosting fuel economy, and as a result shifting up to the higher gears will certainly boost mileage, especially on the highway. Many automatic car users will not have this option, but many automatic gearboxes are intelligent enough to shift up if someone is travelling at a constant speed. Therefore, keeping the speed down and constant is beneficial on two fronts.Braking is one of the principle culprits behind loses in fuel economy, simply because the engine has to work again to build up speed. Breaking intelligently can save a lot of fuel in the long run. For example, if you see a red signal up the road there is no need to hold the accelerator up until the last minute before breaking to a stop. On the highway, closing gaps very quickly and having to break immediately is counterproductive to fuel economy. The key to saving fuel is not only based on the right technological choices, but also the right mindset to foster behaviors that are fuel saving. Even a 50 MPG Toyota Prius can become grossly inefficient with the wrong kind of driver, and therefore becoming knowledgeable and vigilant about fuel savings is not only the key to saving fuel but the key to saving the environment as conscious consumers.