Hypermiling - Saving Gas by Driving Differently
What is hypermiling? According to a a fantastic August 2006 story in the Washington Post, it is a method of increasing your car's gas mileage by making skillful changes in the way you drive, allowing you to save gas and thereby have an easier time withstanding the rising oil and gas prices.
Effective Hypermiling for SUVs and Other Gas-Guzzlers
SUVs and other fuel-thirsty vehicles make good role models for exhibiting the fuel-wasting effects of wind resistance, friction, inertia, momentum and aggressive driving. The bigger and heavier a vehicle is, the more fuel it will waste to accelerate, maintain speed and come to a stop. Also, the more powerful the engine, the more heavily the operator's foot will likely engage the gas pedal.
Owners of SUVs and other fuel-intensive vehicles who want to do their part in the crusade to get as much mileage as possible out of a gallon of fuel should try some of the following hypermiling techniques and may be surprised with the results. If you are stuck driving your current vehicle due to either poor trade-in value, inability to obtain credit, or have resolved to keep your vehicle till the doors fall off, you can still make the best of the situation by driving as fuel-efficiently as possible.
Calculate the Fuel Efficiency of Your Vehicle
Write down your vehicle's mileage when you fill up your tank. The next time you fill up, record your mileage again, and the amount of gas you used. The difference between the first odometer reading and the second is your mileage for the amount of gas you used. Simply divide miles driven by gallons used to get your miles per gallon. Repeat this calculation and compare results routinely as you implement some of the driving techniques that can increase your fuel efficiency.
Speed and Fuel Efficiency
Each vehicle has a range of speeds within which it reaches its optimum fuel efficiency, usually within 45 to 60 miles per hour. Each 5 miles over 60 mph reduces your fuel efficiency by up to 10 percent. Most of us tend drive 10 mph above the speed limit without even realizing it, especially in a large, heavy and powerful vehicle.
Newton was Right
Time spent idling at lights is a pure waste of gas. Avoid coming to a complete stop by coasting up to lights and keeping a generous distance between you and the vehicle ahead; you save gas by accelerating and braking less frequently and more slowly. Aggressive drivers and those driving SUVs, with their higher view of traffic, innocently engage in tailgating, applying their brakes and speeding up rapidly, resulting in poor fuel economy and more accidents. With most auto insurance companies raising their rates to cover SUV and performance vehicles, hypermiling makes more sense than ever.
Reduce Inertia, Tire and Wind Resistance
SUVs are often accessorized with features that are inherently bad for gas mileage. Last year, Michelin completed a study which concluded that overcoming the rolling resistance of some types tires can account for as much as 20 percent of the fuel consumed by an SUV. Unless you are using your SUV for daily off-road excursions, when it comes time to replace your tires, opt for those with a lower rolling resistance to decrease the drag heavy-duty tires impart to your vehicle.
The less weight you are carrying around in your vehicle, the more fuel you will use. Remove any heavy objects you do not routinely need in the vehicle, such as tools, camping gear and in-laws. The drag created by your SUV's roof rack can reduce fuel efficiency by up to 5 percent. Due to the economic and environmental crises we are facing, many of us are not in the position to replace our vehicles with a Toyota Prius or a Chevrolet Aveo, but we can still cut CO2 emissions and improve the fuel efficiency of our gas-guzzlers.
See the hypermiling How-To methods
Hypermiling : Ways to decrease your fuel consumption
- First (and most important) step: Start recording your gas mileage. Easiest way? Use your trip odometer. Method to check your MPG
- Second step: Do you drive agressively and not know it?
- The third step:
How long are you sitting still at red lights?
- The fourth step:
Keeping moving in traffic congestion
- The fifth step:
Slowly accelerate after stops
- The sixth step:
Your cruise control saves gas (but not by using it they way you might think)
Don't forget that you can buy gas-saving parts that improve the effect of hypermiling!
How do you drive? Are you braking a lot?
- You've started recording your miles per gallon already, right?
Get accustomed to wanting to know your MPG... Try to crunch the numbers in your mind as you drive away from each gas station fillup.
- The second step:
Believe it or not... you need to start thinking about -- and becoming aware of -- all the stuff that goes on in your head while you drive.
- Your driving etiquette
- How and when you offer courtesies to other drivers
- Your opinions about other drivers in general
- How you drive when you are in a hurry
- How often you are in a hurry
- What you do when drivers speed up behind you or tailgate you
- And pretty much any other thoughts you have during every driving trip, conscious or subconcious.
... The point of all this being: Ask yourself WHILE YOU DRIVE -- can you possibly give let some of your thoughts focus on having maximum carefulness while driving, including offering buffer space between you and other drivers. when you are not paying attention to other drivers, for whatever reason, does it cause you to use your brakes more than you normally would?
Here's the deal: Drivers apply their brakes between 10 and 25 percent more time than they need to!
Huh??? If drivers leave a big enough buffer between them and the car in front - at least 2 seconds or more - there would be more time to coast before putting on the brakes. And if you see a red light way up ahead, why bother to keep your foot on the gas?
The points to take away from this page:
- People who don't leave much space between their car and the car in front use their brakes more often.
- Braking turns motion into heat via the friction of the brakes, slowing down your car.
- Gas was used by your engine to achieve motion.
So when you apply your brakes, you are turning gasoline into heat instead of using the rest of the motion - by coasting through the space buffer between you and that car ahead, or that red light ahead - that you paid gas money to obtain in the first place.
Are you stopping at red lights for too long?
Guess how many miles per gallon you get when you are sitting at a red light?
Thats right, you are getting ZERO mpg when you are stopped at a red light or any other time you are stuck in traffic and not moving. So the thing to do is: minimize the time that you spend with your car stopped.
Let your foot off the gas the minute you see a red light in front of you. And think ahead, even if you don't see a red light: maybe there is a big street coming up, or maybe there is a 'stale' green light (a light that has been green a long time & you suspect it may go yellow before too long.)
Try to minimize the time you spend fully stopped with your engine idling. The minute -- no, the second -- that you see brakelights in front of you, take your foot off of the accelerator pedal, or hit the cancel button on your cruise control, and stop burning the gas that you know you'll be using up at zero mpg while you are stopped.
A technical approach to reducing traffic jams
Anti-Traffic was "discovered" and described by Electrical Engineer William J. Beaty in a very well written and detailed article in 1998. Check out his groundbreaking research article about negating traffic congestion waves
The methods Beaty identifies in his article are a key to hypermiling, because (1) the gasoline wasted in traffic congestion causes a tremendous nationwide cumulative effect on the demand for fossil fuels, and (2) without traffic jams, we'd all be moving along smoothly in our cars, resulting in less stops and starts, which equals less acceleration (uses gas) and less braking-induced deceleration (which wastes the motion we began when we accelerated.) And of course less time spent stopped, when your car is getting zero miles per gallon.
Fast accelerating burns more gas (=money!)
You use the most gas when you accelerate. For example, to get to a certain speed in 3 seconds, it takes more acceleration (fuel) than it would to reach that same speed in 4 seconds. Some ways to use this information to your advantage are:
- When you start moving after stop at a red light or a stop sign, *and* if you are in a car with an automatic transmission,
give an extra second of time between when you release the brake pedal and when you hit the gas pedal. (Dont do this with
manual transmissions or you could cause an accident though!)
As you probably know, an automatic transmission car will start moving very slowly on its own with no brake applied. You can use this to your advantage, as a form of starting out slowly from a stop, even if you only do it for a second. Then once your car is in motion - however slowly it may be going - you can start accelerating with the gas pedal.
Why this helps: It takes a LOT more energy to get a stopped object moving rather than to get a moving object moving a bit faster (friction forces are involved here). Letting an Automatic transmission car start moving *slowly* under its own very small acceleration -- even just for a second -- will allow you to start using the gas pedal while the car is already in motion. (Note... this of course doesn't work on hills. Use it on flat or downgrade roadways.)
Cruise Control: Not just for highways anymore
Accelerating a bit more slowly will make a *big* difference in your MPG. The "accel" button on your cruise control is a great way to accelerate slowly.
- If you have one, use your car's cruise control. Learn about what it does from your owner's manual, and see this link about
how a cruise control works.
Why use it? Becuase with a cruise control, you can accelerate with very small, defined increments, like 1/2 to 1 MPH per click on the "accel" button. Or you can hold down the accel button & it will continue accelerating, but slowly.
- Keep in mind that the cruise control normally doesn't allow you to turn it on until you reach a certain speed, like 25 MPH. To deal with this, just accelerate slowly up to that speed, then hit the "set" button on the cruise control to turn it on, and then use the "accel" button to go up from there. (Of course, make sure that the road conditions are safe for slow acceleration. Don't dare do this on a freeway onramp for example.)
- While you use the cruise control, you can slow down by turning it off with the cancel button. Make sure to learn
how the decel and accel and set and cancel buttons work in situations where you wont risk an accident. By practicing with
the cruise control, you'll find over time that your thumb becomes very adept at taking care of the accelerating
and decelerating that your foot does during any trip.
Make sure you always keep one thing in mind though: A cruise control does not have the ability to apply brakes! So never, ever let your feet become relaxed, because you'll always need to hit the brakes during your trips. Speaking of brakes, here are some helpful links in case you need to replace yours: Brake Pads, Brake Rotors
Improving Hypermiling Results: Buy the Right Car or Truck Parts
Hypermiling of course can be done without buying any special parts or accessories for your vehicle. That said, the extent that hypermiling helps can be affected by certain parts or accessories available for your car or truck. Here are some specifics, with a link to where you can buy them:
- Performance Air Filters - These flow more freely than your factory air filter, thereby allowing you to push on the accelerator even less to get up to your desired speed.
- Performance Chips - These are computer devices that allow you to control the amount of fuel used when accelerating. While most people buy these to juice up the fuel flow and "go fast", today's performance chips also have gas-saving modes that make your fuel usage more efficient.
- Low Profile Tonneau Covers - These are for truck owners. As air flow goes over the cab of the truck, it then flows into the bed of the truck, which catches the air and prevents it from smoothly passing by. This inefficient airflow makes it so that you have to push the accelerator more to accelerate, thereby consuming gas. A low profile bed cover makes that air flow past the cab more smoothly, thereby allowing acceleration with less effort.
- Air Intake - As with the air filters reference above, air intakes essentially allow for less restrictive air flow into your engine, which in turn means you can push less on the gas pedal to get the acceleration you desire.
- Shocks - If you have worn shocks on your car or truck, then there is a lot of suspension travel. Increased acceleration is needed to counteract that. A set of new shocks minimizes suspension travel and thereby acceleration needed for normal driving.
Check out this video showing some basic hypermiling tips being given on electronic signage at busy intersections... in India!.
Fuel Efficient Driving Encouraged in India
Check out what India is doing to encourage fuel-efficient driving - they have expensive, bright, weatherproof LED signs installed at major intersections with messages telling drivers how to save gas. No advertising given - just encouragement for driving green.
In the video below, you'll see messages about fuel (petrol) savings as related to speed (KMPH) as well as tire (tyre) pressure. The sign text flashes a lot but this is because of slight synchronization differences between the video camera and the rate at which the sign's LED lamps are going on and off. To a normal user, the messages appear just like on any other electronic sign.
This CNN.com Article gives a fantastic explanation of some of the basic concepts behind hypermiling.
Cars used to get higher mileage in the past, especially during the 1980's, since we had learned something from the 1973 oil embargo. Remember the 50 MPG Diesel Rabbit? And a 1989 Mazda Pickup - B2200 - got 33 miles per gallon on the highway, yet the currently available pickup - a B2600 - gets in the neighborhood of 20 MPG. Huh?! Think about the money ramifications: MPG then, now. Gasoline consumption then, now. Fuel prices then, now. Who is getting rich?
Remember the window sticker on your car when you bought it? Did you ever get the miles per gallon that it showed? I certainly never did. Normally I got as much as 1/3 less MPG than the value advertised.