Monday, January 5, 2009

Hypermiling

Welcome to 2009. If you made a resolution to be a little greener or save a little money, here is one idea. 

Have you heard of Hypermiling? Hypermiling was named the 2008 Word of the Year by the New Oxford American Dictionary.

In short, Hypermiling is driving for maximum fuel efficiency. You can use many of the techniques in any car, even a gas guzzler. Some avid hypermilers have achieved more than double the rated MPG. That is impressive considering that they do this by changing how they drive. 

In search of extreme MPG, some take it even further and modify their rides. This is known as "ecomodding". Simple mods are things like removing the roof rack, radio antenna, windshield wipers and side mirrors.

Let's stick with just hypermiling for now.

There are lots of techniques that hypermilers use. These are a toolkit and the right tool depends on the vehicle in question (hybrid, automatic, manual...), the road (hills, flat, curves...), and traffic.

Most drivers try to get as quickly as possible from point A to B. Let's turn that on its head and try to get there as efficiently as possible. Some of the hypermiling basics with broad application include:
  1. Remove Extra Weight
  2. Correct Tire Pressure
  3. Avoid Idling
  4. Gradual Acceleration and Stopping
  5. Anticipatory Focus
  6. Roller-coaster Driving
#1 Take the junk out of the trunk. Remove the extra weight so there's less to mass to accelerate each time you take-off. This saves gas (and brake pads). So take your golf clubs or that 40 pound dog food bag out unless you need them on that trip.

#2 Keep your tires properly inflated, This simple and improves your mileage. We all heard this one during the presidential campaign.

#3 Avoid Idling: If you are going to be stopped for more than 30 seconds and you can safely do so, turn off your engine. Every minute your engine idles equates to about 1/2 mile of wasted fuel. Hybrids (and EVs) get this one for free.

These next three are actually driving techniques and I want to stress that they need to be done safely and legally. Saving a few bucks on gas does not help you if you have to pay to get your car towed away from an accident and repaired. 

#4 Gradual acceleration allows your engine to run in its more efficient lower RPM range. And you will likely develop a gap between you and the car in front of you. You'll need this to allow for longer stopping distances.

If you coast to a stop, then it will take a longer distance, this means that you'll have to start sooner and therefor take your foot off the gas sooner. Both are pluses. This also allows more time for the traffic situation ahead to change so maybe you won't have to stop at all. This could even mean that you pass normal drivers that had to stop.

#5 Anticipatory Focus. This is really just "Attentive Driving", being aware of your surroundings and what is coming up. If there is a traffic light up ahead, time it so you can roll on through without hitting the brakes. Even if you have regenerative brakes, preserving momentum is more efficient.

#6 Roller-coaster Driving or gravity assisted driving as I like to refer to it. Typically drivers will brake on the downhill and then hit the gas on the uphill. Hypermilers would coast down the hill allowing gravity to accelerate them and then dissipate this extra velocity as they climb the next hill. And if you are going the speed limit when you approach the downhill (rather than 10MPH over it), you can legally allow gravity to accelerate you.    

To use these, leave a little early so you are not rushed.  You can arrive less stressed and feeling that you did a little something to help conserve. Many of the hypermiling methods also work to improve the electric range in PHEVs or EVs. You get a better Watts per mile and the batteries can take you farther.

Feedback is what you need so you know when you are getting it right. Many cars include an instantaneous MPG readout. The new Eco-Assist Gauge Cluster in the 2009 Honda Insight takes this feedback to the next level. If your car does not have an MPG read out, you can buy an after market one that plugs in to the diagnostic port and display the info.

Funny sidebar: when I was searching for info for this story, one of the ads that popped up said "drive like there is no tomorrow".  To which I thought, 'boy did they buy the wrong keywords'. Hypermiling is driving like there is a tomorrow. If you drive like there is no tomorrow, that may become self-fulfilling.

Links:
Audio from EV Cast EVcast: Hypermiling!

No comments: