Putting the Stereotypical Notion of a Tightwad on its Tush

Cost Comparison: Hypermiling vs. Standard Driving

Blame the economy, your state legislature’s decision to increase the taxes, or your own driving habits: a tank of gas isn’t getting you as far as it used to. Over the past year, the average price for a gallon of gas has soared nearly $0.50, according to AAA’s Daily Fuel Gauge Report. In my neck of the woods, a gallon of gas costs $3.50; with my 18-gallon tank, I was paying more than $60 dollars every time I filled up.

I was determined to save money and avoid the pain at the pump. I came up with a list – and subsequently scratched off – a list of ideas:

  • I could cut out all unnecessary trips, consolidating my daily trips to the grocery store (I’m the type of person who likes to shop for ingredients day to day instead of in bulk) into a single weekly trip, eliminating my daughter’s cross-town playdates, and attending Sunday services at a church closer to our neighborhood. Nope; while cutting down on these trips might save me money, it would be at the cost of convenience – and that’s not a price I’m willing to pay.
  • I could sell my semi-fuel efficient Hyundai Sonata and buy a flex-fuel vehicle instead. Yeah, this didn’t make sense to me either. While I’d ultimately reap the financial benefits of a more fuel efficient vehicle, it isn’t economically feasible for my family to trade in cars right now.
  • I could put my car in park and rely on public transportation instead. The nearest bus stop is a mile from my house, involving a walk down a busy road – not exactly a safe option when you consider I run most of my errands accompanied by a three-year-old and a nine-month-old.

Ultimately, I came up with one and only one option to curtail my fuel costs: changing the way I drive. Now, there are two schools of thought here. I could always drive the speed limit, avoid aggressive driving, and resist the urge to put the pedal to the metal, so to speak. The U.S. Department of Energy’s site on fuel economy estimates these simple changes can save you five percent on fuel costs for city driving and up to a third of fuel costs for highway driving.

The How-Tos of Hypermiling

The second school of thought was more extreme: hypermiling. My frugal father has practiced this extreme form of driving for the past five years in his 2001 BMW 325i. Hypermiling completely changes the way you drive. The goal is to use as little gas as possible, meaning you have to lay off the gas pedal and in many cases the brake as well. Some of the finer points of hypermiling, a term coined by Wayne Gerdes, include:

  • Avoid idling, which drains your gas tank without giving you any mileage to show for it. Gerdes even suggests shutting down your car if you’ll be idling for longer than seven seconds.
  • Turning off your car’s four-wheel drive function, since the EPA measures fuel economy for vehicles based on two-wheel drive.
  • Changing when you drive. Your car is less fuel-efficient in the extreme cold, since it has to burn gas simply to heat the vehicle.
  • Turning off your car’s air conditioner. The AC can decrease your fuel mileage by as much as 30 percent.
  • Keeping a slow, steady speed. Your car’s fuel mileage plummets once you top 60 miles per hour. Driving at a slower speed – and maintaining that speed without accelerating – increases your gas mileage.
  • Making your car more aerodynamic. There’s a reason why small vehicles typically get better gas mileage than large vans, trucks, and SUVs. Avoid driving with a roof rack or luggage tied to any part of your vehicle’s exterior. This extra baggage also adds to your vehicle’s weight, which decreases your fuel efficiency as well.
  • Properly maintaining your vehicle. Make sure your tires are inflated to the exact specifications outlined by the manufacturer, tuning the engine, and regularly changing the oil and air filters.

Cost Comparison: The Experiment

I wanted to see just how much money I could save by adopting the habits of a veteran hypermiler, but in order to do a true cost comparison, I needed to isolate the variables. I decided I would compare the costs of standard driving the first week of January and evaluate the merits of hypermiling the second. This way, the weather conditions would be similar.

On January 4th, I filled up my gas tank until it was full. Over the next seven days, I put 171 miles on my Sonata, including:

  • Six trips to and from my daughter’s preschool (three roundtrips to drop her off and three subsequent roundtrips to pick her up)
  • Four trips to the grocery store
  • Five trips to the YMCA
  • One playdate with a friend who lives 17 miles from my house
  • One trip to Sunday services at our church, which is located 9 miles from my house

One week later, I visited the same gas station, filling up my tank using the same pump – again, in an attempt to limit the variables. I put 6.75 gallons into my tank. Doing the math – 171 / 6.75 – I figure I got roughly 25.3 miles per gallon during my week of normal driving. That’s slightly higher than the EPA standard for my vehicle – a 2008 Hyundai Sonata – which is 24 miles per gallon.

During the seven-day period following January 11th, I drove 203 miles in my car. My trips included all those listed for the week of January 4th, as well as a 30 mile roundtrip to a children’s museum in a nearby town for a birthday party for one of my daughter’s friends.

When I filled up my car the next week, I put 6.42 gallons into my tank. At this point, I already knew my hypermiling experiment had been a success, since I’d had to put more gas into my car – despite driving fewer miles – the week before. Breaking down the numbers – 203 / 6.42 – I figure I got roughly 31.6 miles per gallon while hypermiling.

Is It Worth It?

Just examining the numbers – 25.3 miles per gallon while driving “normally” vs. 31.6 miles per gallon while hypermiling – it seems pretty obvious that I managed to stretch my fuel efficiency farther by changing my driving habits. I was able to increase my gas mileage by nearly 25 percent in just a week’s time. I usually spend $175 a month to fill my gas tank, so if I continue to hypermile to my destinations, I should be able to cut that by a quarter to just $131.25, saving me $43.75 every month. Extrapolate that over a year’s time, and that’s an additional $525 back in my pocket.

I also know I didn’t go to the extreme limits of hypermiling. For one thing, I didn’t change when or to where I drove. I went about my normal errands, even though getting to the grocery store consists of driving up a large hill on my way home – a no-no of serious hypermiling. The online community CleanMPG asserts veteran hypermilers should be able to increase their fuel mileage 40 percent over the EPA standard for their vehicle; in my case, that would mean getting 33.6 miles per gallon in my ’08 Sonata.

But was my foray into hypermiling worth it? In my opinion, absolutely. I mean, how else can you save $500 a year without cutting back or limiting yourself? My husband – and anyone else who road in my vehicle during my week-long hypermiling adventure – might disagree. My best friend was gravely embarrassed (on my behalf) when I turned the car off at a series of red lights in the middle of town. My husband was annoyed when I lifted my foot off the gas half a mile from a stop sign, reaching the intersection at a snail’s pace. Even my three-year-old daughter screamed in terror as I coasted down a hill a bit too fast in order to stretch my gas mileage to the limit.

While I may not pursue the extremes of hypermiling in the future, I’m convinced that the cost comparison of extreme driving vs. normal driving shows changing even a few of your driving habits is well worth your time… and, best of all, well worth your money!

3 Responses to Cost Comparison: Hypermiling vs. Standard Driving

  1. What a great experiment!
    We’re huge lovers of “coasting”. When driving our (manual transmission) car, we put it into neutral and coast along if we’re slowing down in traffic or coming up to a red light, rather than keeping it in drive with the foot on the gas. I’ve never done a cost analysis of it… but now I’m tempted to see what kind of a differece it makes!

  2. @ Kristin and Julie, I hope you will give it a try – and if you do, come back here and let me know how it worked for you! The bullet points I really focused most on involved lightening my vehicle’s load (I had a ton of crap in the trunk), driving a slower, constant speed (hard to cut down on all that accelerating, but I think this was the biggest payoff) and taking advantage of my vehicle’s ability to coast – just like Julie mentioned! Good luck, and keep me updated!

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