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An Eco-Driving Primer

Squeezing every mile out of a gallon.

by on Apr.22, 2009

It doesn't take much work to save several mpg and turn yourself into an Eco-Driver.

It doesn't take much work to save several mpg and turn yourself into an Eco-Driver.

It’s not easy getting 30 mpg.  Especially not if you’re driving the new 2010 Toyota Prius, which is rated at a combined 50 miles to the gallon.  But with my afternoon driving partner, that’s precisely what we set out to do, breaking just about every rule you could think of to ensure poor mileage.

In other words, we drove the way many folks do every single day, racing up to stoplights, then slamming on the brakes, revving the engines while we waited.  We used every opportunity to pass, tailgated almost constantly and launched off each light with the accelerator pedal pressed flat to the floor.

Even that yielded what most folks would consider great fuel economy in the Prius – but we got only a little more than half what the hybrid-electric vehicle was rated to deliver.  Several colleagues, driving with the intent to maximize their mileage, on the other hand, turned in fuel economy numbers of more than 70 mpg, at the end of the afternoon.

Subscribe to TheDetroitBureau.comEvery car is rated by the federal government as to what mileage you can expect, both in the city and on the highway.  Changes to the testing process, in 2008, made the Munroney sticker, on the side of each new vehicle, more accurate than ever.  Even so, as they say, “mileage may vary.”  All sorts of factors can come into play: the fuel you use, traffic conditions, even the altitude you live at.  But the most important factor of all is you, the driver.

Even the most mild-mannered motorist can pick up a few miles a gallon by learning some basic eco-driving tips.  And for more aggressive drivers – notice me raising my own hand – the impact can be as much as 30 to 40 percent or more.

But in your pursuit of maximum mileage, we also need warn you to be courteous and considerate of other drivers, lest you find yourself inspiring some serious road rage.  Sure, the speed limit in Los Angeles’s HOV lanes may be just 65, but if you’ve got a mile of traffic backed up, everyone wanting to do 80, get out of the way.

The basics of eco-driving are easy to master:

  • Don’t slam the accelerator when the light turns green.  Squeeze the pedal slowly and evenly.  Some experts suggest you imagine there’s an egg between your foot and the throttle pedal.  Or think about having a cup of hot coffee with no lid sitting on your lap;
  • And when you’re approaching a light, ease up on the gas some distance back – without bringing everyone else behind you to a screeching halt.  Coast to the corner and avoid that nervous habit of revving the throttle while you’re waiting;
  • The same thing works when you’re getting ready to make a turn.  Slow, but maintain enough momentum to carry yourself around the corner before reapplying the throttle;
  • Many eco-drivers will coast on hills and coming down a ramp, even  putting the car in neutral – which is easy if it’s a stick.  That approach is debatable and does pose a potential liability.  If something requires you to accelerate out of trouble, you may not have enough time to react;
  • Most modern cars are geared to deliver optimum fuel economy at speeds of around 55 to 65 mph.  Stay to the right and smile at the other drivers burning excess fuel;
  • Keep engine RPMs down, usually below 2,000 revs.

Many modern cars come equipped with shift warning lights designed to tell you the optimum time to shift a vehicle with a manual transmission.  While some experts debate the value, Nissan claims its research shows a savvy shifter can improve fuel efficiency in such conditions by as much as 18 percent.  The automaker is also considering a “smart” eco-pedal that would give light resistance if you try to accelerate too quickly.  Look for it to debut around the 2011 model-year.

Many cars also come equipped with instant fuel economy gauges.  Use them regularly and you’ll get to know what’s the most fuel-efficient way to drive your own vehicle.  But don’t stare at the read-out — particularly, those high-tech displays common on hybrids like the Toyota Prius.  They may be entertaining, but you don’t want to take your eyes off the road for long.  A wrecker uses a lot of gas to haul your car back to the body shop.

While there are plenty of ways to improve mileage through careful, rather than aggressive driving, don’t forget the common-sense ways to ensure your car delivers the mileage it was designed for.

Skip those engine water injectors, the fuel line magnets and all those other accessories you see advertised on infomercials.  They don’t work.  What does is keeping your car properly tuned.  And few things can impact both your performance, mileage – and safety – like a properly-maintained set of tires.

President Obama got it right, a few months ago, when he told Americans to keep those four black donuts correctly inflated.  If your tires are low, they’ll lose grip, wear out quicker, potentially blow out – and steal perhaps 10 percent of your fuel economy.  Check tire pressure before you start driving, or after the cars been sitting for at least an hour, preferably out of the hot sun.  Repeat every few months, more often if you drive a lot.

And while you’re at it, check the trunk or cargo bed to see if you’re hauling things around needlessly.  The rule of thumb is that you’ll lose about 1 mpg for every extra 100 pounds in vehicle weight.

Courtesy is a critical factor if you’re planning to perfect your eco-driving.  There’s no reason to try to save the planet by punishing your fellow drivers, no matter how piggish they may seem.  Just smile, move out of the way and take satisfaction in knowing you’re only green in spirit, but saving plenty of green from your bank account.

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One Response to “An Eco-Driving Primer”

  1. Kyle P says:

    “Many eco-drivers will coast on hills and coming down a ramp, even putting the car in neutral – which is easy if it’s a stick. That approach is debatable and does pose a potential liability. If something requires you to accelerate out of trouble, you may not have enough time to react;”

    Let’s kill two birds with one stone here. Leave it in gear! If the vehicle is in neutral you have the added risk of not being able to accelerate if need be, and your engine must IDLE, burning gas to do so. However, most recent (to the last decade) EFI vehicles will actually completely shut off the fuel injectors when the momentum of the vehicle going down a hill is sufficient to keep the engine turning above its idle speed. To get the injectors to shut off, just leave the car in gear and do not apply any throttle. Worst case scenario, it will burn as much fuel in this state as it would idling, but it removes the safety concern.

    Kyle P.
    Colorado State University
    Automotive Industry Management ’09