A recent blog entry by Joshia got me thinking about ways to deal with rising gas prices. In our responses to his blog, the readers debated the relative merits of hybrids and high MPG conventional vehicles.

Meanwhile, Alli and I are 2 months away from owning her car 100%, so as an American, my natural instinct is to sell that car and buy a shiny new one. In this dream scenario, the new toy would be a Toyota Highlander Hybrid. However, since I live in the real world (debatable, if you know me), I’ve been considering more economical approaches to the challenge of getting myself, my family, and our stuff from Point A to Point B. Amazingly-smart guy that I am, I’ve come up with the perfect solution.

The Perfect Solution

[Before continuing, let me say this: First, I'm going to state the perfect solution, then I'm going to back it up with some sound arguments. Now, the statement is pretty short (you've probably already jumped ahead and read it by now anyway), but the arguments are lengthy. So, if you don't like longish blogs, then just take my word that I have thought this through, and that my solution really is perfect. If you do like longish blogs, please hold your applause until the end.]

The perfect solution is to keep the cars we have for now, and to DRIVE THEM MORE EFFECIENTLY.

Driving more efficiently involves two objectively measurable driving changes aimed at reducing existing fuel “waste.”

The first is driving slower - specifically, driving slower on the interstate and other places where high speeds are common. According to numerous sources (which skeptics can google for themselves), the typical automobile consumes 20% more fuel driving 65 MPH compared to 55 MPH. Driving 70 MPH consumes 25% more fuel than 55. Beyond 70, the fuel consumption per MPH curve becomes exponentially steeper. Driving 55* instead of 65 saves about $1.50 per tank of gas assuming 20% of driving is at high-speeds. Based on current gas prices, this is equivalent to a 10-cent per gallon savings.

The second change is increasing the time between accelerating and braking when driving (i.e. coasting). In most situations, I estimate the time coasting to be five seconds or less. Increasing coasting will increase fuel economy. The key to increasing coasting is anticipation. Instead of only considering what’s happening two car-lengths ahead, drivers should be aware of traffic a block (or farther) away and anticipate what’s likely to happen.

For example, heading north on Tennessee Ave. (leaving Saint Elmo), between where Saint Elmo Ave. ends and Tennessee meets Broad Street, there are two traffic lights (one at the foot of the Winn Dixie BiLo shopping center (W. 38th St.), and the other after the railroad tunnel (W. 37th St.). During normal driving hours, the chances of being stopped at each light is about 50-50. Combined, there’s only a 25% chance that a driver won’t be stopped by either light (or the cars ahead of them stopping). Anticipating whether to accelerate when approaching these lights is difficult because they are obscured by the Mr. T’s Pizza building, and the railroad tunnel respectively.

Because of these obstructions, line-of-site is about 220 ft. to the W. 38th St. traffic light and about 250 ft. to the W. 37th St. traffic light. At 30 MPH (the speed limit on that part of TN. Av.) a driver?s estimated overall stopping distance** is 75 ft. (dry conditions) to 120 ft. (wet pavement***). So, after subtracting an average of 80 ft. needed to stop, the time between seeing the light and beginning braking is only 3.2 and 3.9 seconds respectively. So, the average driver relying on what’s two car-lengths ahead, could only coast for 3 to 4 seconds before having to apply their brakes. However, if consideration is given that 75% of the time the driver will get stopped by at least one of these lights, they could anticipate needing to stop and begin coasting before actually seeing the traffic lights ahead.

The cost savings of anticipating traffic ahead and thereby maximizing coasting is difficult to estimate since there are so many variables. However, extending coasting distance an additional half-mile per ten mile trip (which I believe is possible in my own situation) would cut fuel consumption by about 5%. Based on current gas prices, this is equivalent to a 13-cent per gallon savings.

So, after taking into consideration the cost of a new car verses it?s fuel savings, I?ve decided that I can modify my existing driving habits and save more money in the short term (two to four years is about as long as i can hold out and keep from buying a shiny new toy car - hybrid or otherwise). There you have it, the perfect solution. You may now applaud.

* It should also be noted that 55 isn?t a magical speed at which cars operate most efficiently. As a rule, cars are most efficient operated at low RPM in their highest gear.

** Overall stopping distance is a combination of reaction time and average braking distance.

*** Interestingly, the word “pavement” in Great Britain means “sidewalk”. So, if you’re driving 30 MPH on pavement in the UK, you’re a menace to society and should be incarcerated.

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