Hypermiling BasicsJuly 8, 2010 | in Defensive Driving Online
Hypermiling. The first time I heard the word, I imagined some strange engine malfunction, or perhaps a kind of car-induced anxiety attack, the automotive equivalent of hyperventilating. Of course, neither of these vague impressions was remotely correct. In reality, hypermiling is many things: extreme cost-cutting strategy, environmentally friendly practice, competitive sport, and 2008 Word of the Year (according to the New Oxford American Dictionary.)
Hypermiling is, in short, the pursuit of the maximum number of miles per gallon. Hypermilers aim to exceed the EPA miles-per-gallon rating of any given car. Hypermilers regularly practice many of the basic gas-conservation measures I described in my previous post on the subject; however, they also implement an array of advanced techniques that can result in amazing gas savings. Experienced hypermilers regularly achieve over 100 MPG (when driving Hybrids.) For example, at the 2006 Hybridfest MPG Challenge in Madison, Wisconsin, the winning driver (Wayne Gerdes) averaged 183 MPG over the assigned route.
Some critics, including the American Automobile Association, have argued that hypermiling practices can be dangerous and, in some cases, illegal (overinflating tires and coasting with the engine off are two examples often cited in this debate.) In response, hypermiling associations have argued that true hypermilers would never endorse an illegal practice and that, in fact, hypermilers are more conscientious about practicing safe driving measures often ignored by others, such as paying detailed attention to their surroundings, anticipating traffic hazards, and driving at or below posted speed limits.
Like many things, hypermiling practices are tools, which can be used to good and bad effect. In this post, I’ll describe a few of the most common hypermiling measures, although dozens, if not hundreds, more exist. Bear in mind that a journey of a thousand miles begins with a single step. You won’t be able to achieve 100 MPG (or more) overnight; many of these techniques take some time and practice to adjust to. Experienced hypermilers recommend adding techniques to your toolbox one at a time, and testing them out first in an empty parking lot or other safe practice area. When sharing a road with others, don’t ever attempt maneuvers that you don’t feel 100% comfortable executing.
Obviously, the kind of car you drive will have a huge impact on the MPG you can achieve. Hybrids, such as the Honda Insight or Toyota Prius, are far more fuel-efficient than the average car. Watch out for an upcoming entry on purchasing, owning, and driving a hybrid, and entries on other types of fuel-efficient technologies (such as bio-diesel.) However, many of these hypermiling techniques will also produce noticeable increases in fuel efficiency in “normal” cars.
Driving a manual transmission, rather than automatic transmission, can also aid hypermiling. The greater control over the car that manual transmission gives you makes many hypermiling maneuvers, such as coasting, easier.
Finally, consider investing in an Instantaneous Fuel Consumption Display (unless you drive a car, like the Toyota Prius, that comes equipped with such a device.) There are a number of different kinds of devices that can be used to monitor fuel consumption; you may want to speak to your mechanic about which would best suit your budget and model of car. Having such a device is perhaps one of the best ways to train yourself to be a more efficient driver, as you can easily see the results of different techniques as you apply them.
EIGHT KEY STRATEGIES
First and foremost, hypermiling begins with basic fuel economy strategies: avoid sudden braking and acceleration, avoid unnecessary idling, try not to drive in heavy traffic, use air condition sparingly, combine several short trips into one longer one, and don’t drive too fast.
However, hypermilers go above and beyond these basic common sense tenets with a number of advanced maneuvers:
1. Ridge Riding
This is a way of avoiding the “drag” caused when water or snow accumulates in the troughs worn into the lanes on the road. Basically, most drivers drive in the center of the lane, which produces uneven wear on the pavement, creating ridges and troughs. (These depressions are slight but can have a noticeable impact.) Instead of driving in these slight depressions, drive on the “ridges” on either side, so that the car has one wheel on the center ridge and the other on the ridge on the right or left side of lane. According to some hypermiling proponents, this technique has the added safety benefit of causing other drivers to take notice of your unusual positioning in the lane, and hence they will drive with greater awareness.
2. Anticipate Potential Obstacles
Driving at a steady speed, without stopping or accelerating, is a great way to increase gas mileage, as acceleration burns excess gas. For this reason, hypermilers maintain an awareness of road conditions in the distance, so that they can anticipate and avoid potential obstacles in order to maintain a constant speed.
3. Driving With Load (DWL)
Essentially, driving with load means maintaining a constant fuel consumption rate as you pass over hilly terrain. Say you have cruise control set. Cruise control keeps your car at a constant speed; however, this means that your engine has to exert more power to maintain this speed when you are going up a hill. In DWL, you maintain a constant fuel consumption instead of a constant speed. If you have an instantaneous fuel consumption display, you can use this device to make sure that you maintain constant fuel consumption. If you don’t have an IFCD, however, you can approximate constant fuel consumption by keeping the accelerator “locked” at a fixed angle as you move up and over the hill.
4. Driving Without Brakes (DWB)
Basically, when driving in heavy traffic, pretend you don’t have brakes. Create a large buffer zone around your car, so that you have time to react to changes in traffic speed without actually having to stop. This can take some patience, especially as other cars will likely cut into your buffer space. However, this can ultimately be a safer and more relaxing way to drive in traffic. The goal is to achieve a constant slow speed despite the “stop and go” of cars around you.
5. Smart Braking
When you brake, your brakes convert the kinetic energy of your moving car into heat, so that your car slows down. Essentially, braking is like “burning” up gasoline without making any forward progress. For this reason, hypermilers practice smart braking. First, anticipate lights; start slowing down way before the red light so that, ideally, you will still be moving when the light changes and the traffic moves forward again. The goal is to continue rolling without actually coming to a dead stop. (Remember, however, that rolling through stop signs is illegal. Safety and legality are still more important than fuel economy.)
If you are stopping on a downhill plane, try to stop some ways before the end of the hill so that you can use the slope to get your car rolling again without having to accelerate. If stopping near or on an uphill, try to roll as far up the hill as possible before coming to a complete stop, to avoid having to accelerate uphill.
6. Rabbit Timing
This is related to smart braking and is a technique for maximizing fuel economy when driving near lights with motion sensors. If you see a red, yellow, or stale green light ahead, slow down and allow another car to pass you and “trip” the motion sensor, so that the light is green by the time you get there, and you can continue through without stopping.
7. Smart Parking
Remember that your car is least fuel-efficient when the engine is cold. This means that you want to execute most of your parking maneuvers when the engine is warm. For this reason, reverse into parking spaces, so that you can easily pull away. If possible, seek out parking spaces on an incline, so that you will be able to roll out of the space, aiding your acceleration with a “cold” engine. Parking in the sun can also help to keep your engine warm and increase efficiency.
8. Engine Off Coasting
This is the limit of my personal hypermiling comfort zone. When slowing down or moving downhill, some hypermilers recommend engine-off coasting as a means to boost efficiency. This involves shifting to neutral, turning off the engine by setting the ignition key to IG-I, then turning it back to IG-II to activate the electronics so that the steering wheel doesn’t lock. However, power steering and power braking functions are likely to be lost. This most easily practiced in a manual transmission car without power steering.
However, this is one of the “borderline” hypermiling techniques that can potentially be dangerous and even illegal in some places. If you drive a manual transmission car, coasting in neutral with the engine still running is a safer, albeit less fuel efficient, alternative.
These are a few basic strategies. However, there are dozens more. If you do catch the hypermiling bug, you may want to check out http://www.cleanmpg.com/, which offers both introductions to hypermiling basics and forums for sharing more advanced tips, and http://www.ecomodder.com/, which offers a comprehensive list of 100+ hypermiling tips.
Even if you don’t become a committed hypermiler, incorporating one or more of these techniques into your daily commute could still help you to conserve gas and save money.
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