Hypermiling

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Hypermiling is the act of driving using techniques that maximize fuel economy. Those who practice these techniques are referred to as "hypermilers."

Hypermiling is defined by the New Oxford American Dictionary as the attempt to maximize gas mileage by making fuel-conserving adjustments to one's vehicle and one's driving techniques ^[1].

The term has been popularized by Wayne Gerdes, who has appeared in the media many times to talk about hypermiling,^[2] and is known to hold the record for gas mileage in some common vehicles, including 30 miles per gallon (mpg) in an Acura MDX and 59 mpg in a Honda Accord. In the article, a trip with Gerdes is described as "..as the vehicle rolls forward really slowly—I notice that all four windows are closed and the AC is off. I'm sitting in one of the most technologically advanced cars in the world, and it feels like I'm trapped in a fanless tollbooth in Biloxi, Mississippi, in August... most of the traffic is zipping past at 75 or so, but Wayne hovers around 50 mph."^[3] In 2008, the word hypermiling was selected as the best new word of the year by New Oxford American Dictionary.^[4]

Hypermiling, which can be practiced in any vehicle regardless of its fuel economy, has gained in popularity as a result of the rise in gasoline prices during the 2000s.^[5] While common techniques can be carried out by average motorists making minor changes in their driving habits, many hypermilers use more advanced techniques, some of which are illegal in most if not all jurisdictions.^[6]

Contents 1 Techniques 1.1 Common 1.2 Maintenance 1.3 Common hypermiling terms 1.4 Extreme 2 Safety and awareness program 3 Hypermiling as a sport 4 See also 5 References

[edit] Techniques

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[edit] Common

Drivers can increase a vehicle's fuel efficiency by remaining focused while driving and anticipating the need to brake or accelerate. Hypermilers seek to minimize both braking and rapid acceleration. Another way to improve fuel economy is by planning routes in advance to determine the shortest distance and fewest stops. Fuel can be saved by shutting the engine off, rather than allowing it to idle while stopped or parked. Also, drivers should be conscious of other behaviors that may potentially sap a vehicle's fuel such as running the air conditioning or driving with the windows down.^[7]

[edit] Maintenance

• Properly inflating tires
• Reducing weight load by removing unnecessary objects from vehicle

[edit] Common hypermiling terms

Common terms used in hypermiling are:^[8]

• FE - fuel economy
• DWB - driving without brakes
• DWL - driving with load
• FAS - forced auto stop, basically coasting with the engine off
• P&G - pulse and glide
• ICE - internal combustion engine
• PP - potential parking
• RR - ridge riding
• SHM - super highway mode
• SAHM - super Atkinson highway mode
• rabbit timing
• smart braking
• face out

[edit] Extreme

Generally, the recommended way to hypermile is using only the common techniques. However, extreme hypermilers have been known to use controversial and illegal techniques:

• drafting behind trucks, decreasing awareness of the road ahead and increasing the possibility of a rear-end collision
• driving far below the speed limit at times, disrupting the normal flow of traffic
• taking sharp curves at high speeds to avoid losing energy to braking
• coasting with the engine off, with the resulting loss of power steering and power brakes
• passing or rolling through red lights or stop signs in areas of low traffic
• over-inflating tires to reduce rolling resistance, sometimes to twice the manufacturer's specifications or more

The benefits of turning off the engine while stopped at lights are questionable. This can be difficult to do properly. Though the engine does not burn fuel while it is off, the motorist may feel pressured to rapidly start the car and accelerate when the light turns green, thereby using more fuel and defeating the purpose of turning the engine off. Starts to the engine also consume some fuel, though the amount varies by vehicle. Some estimates are that the engine uses as much fuel to start up while still hot as it would during 30 seconds of idling^{[citation needed]}, although this only applies for carburetted engines^{[citation needed]}. Fuel injected engines use much less during startup^{[citation needed]}. Natural Resources Canada indicates that this trade-off time is about 10 seconds^[9]. Using this method also puts additional wear-and-tear on the starter motor and other components which can lead to higher maintenance costs later on.

Using any one of these techniques presents a safety hazard, not just for the participant, but others on the road as well. Coasting with the engine off promotes two factors that set up a hypermiler for disaster. The engine of a car not only helps move it but it also helps it stop and steer as well. Depending on the vehicle, if the engine turns off, so does power steering assist and so does the vacuum assist to aid with braking. In many places, driving a car that is coasting out of gear or with the engine off is illegal.

[edit] Safety and awareness program

Hypermiling has come under fire from several quarters due to claims of dangerous or unlawful behavior by some hypermilers.^[10] As a result the Hypermiling Safety Foundation was formed in August 2008 to promote a safety and public awareness program, advocating legal fuel-saving techniques.^[11]

[edit] Hypermiling as a sport

In some places, hypermiling contests have been held to see who can get the highest mpg on a selected course.

The most recent Maximum Fuel Economy contest was held in Elkhart, Indiana at the Fuel Economy World Championships, where world records for the Honda Insight (213 mpg round trip), Toyota Prius (136 mpg round trip) and the Ford Escape Hybrid (76 mpg round trip) were achieved, albeit having been achieved while rolling through all stop signs and having the vehicle tires inflated well beyond recommended specifications.^[12]

Another contest is the Tour to the Shore, held in New Jersey, which evaluates drivers of cars and trucks.^[13]

Gerdes and a team of six hold the current record for the most miles achieved out of a single tank of gas with 2254 miles from the 13.7-gallon tank of a Honda Insight, an average of 164.53 mpg for the entire distance.^[14]

[edit] See also

• Rat running
• Shunpiking

[edit] References