Reducing Fuel usage in your Car

I was recently reading on vehicle efficiency and how it has changed throughout history, and I stumbled upon the term Hypermiling. Hypermiling is basically driving with efficiency in mind, to get the best possible MPG (miles per gallon) on your vehicle. The hypermiling enthusiast, or the hyper-milers, have developed a lot of crazy techniques to achieve extraordinary MPGs way above the EPA specification of their car. I won’t go into detail on each of these techniques, but two of the more extreme techniques I remember are:

  • turning the vehicle off while driving, when coasting speed gets low, turn engine on, accelerate to higher speed and repeat process
  • tailgating trucks to reduce drag, aka drafting

Other techniques are:

  • turn the vehicle off instead of idling the engine during stop signs and red lights
  • reduce or eliminate the use of the air conditioner and electronics
  • drive smart/efficiently
  • inflate tires above OEM specifications

As for my thought on some of these techniques, I’m all for reduced gas consumption and saving money, but turning the vehicle off while driving and drafting other vehicles is plain dangerous and reckless. It’s not worth the extra 5-10 MPG. As for turning off the vehicle while idling, sure there is no harm there, maybe some premature wear of the starter and battery. But I believe that just driving smart can increase anyone’s MPG by at least 10%!

How can you drive smart?

Well I already put my turn signals and obey the traffic laws while driving courteously (sure you do), isn’t that enough?

Not if you want to reduce your fuel usage and fuel costs!

If you get off the green light and accelerate to 50mph to only have to brake to a complete stop some 500 feet later at the next red light, you’re unnecessarily wasting gas and wearing down your brake pads.

If there’s a stop light or traffic up ahead, but you keep the accelerator pressed and wait to brake until the last moment, then you just wasted gas.

If you’re in light-medium traffic and your foot is dancing between the accelerator and brake pedal, then you might very likely be wasting gas.

In all these scenarios, if you study traffic ahead and predict the behavior of other drivers, you can reduce fuel usage by letting the momentum of the car take you into the red light. Leaving some space between you and the car in front will greatly help you with this.

After all this reading on hypermiling, I decided to track my own MPG. The only technique I will use is driving smart. I won’t over-inflate my tires by 10 psi (uneven/premature wear) as the savings it would give would cost me in replacing the tires a lot sooner. 2-3 psi over will be okay for me. My car is a 2015 Corolla LE with an MPG rating of 29c and 37h. C is for city and h for highway. With all the stop and go in the city, you will use more fuel and have a lower efficiency since accelerating will consume fuel faster. If you drive half and half between the city and the highway, you get an average 33mpg. My goal is to achieve the highway 37mpg or better, even when driving in the city.

Some background on my car conditions for these next data plots:

  • Car has over 50k miles when I started tracking mpg on my own
  • Car still has original tires since thread and wear are good and even, will replace at around 60k-65k miles or when needed
  • Tire pressure is around 33psi, just a bit over the 32psi recommendation to compensate for winter temperatures
  • Car is driven between an equal mix of city and highway
  • My amazing Mrs. Monster sometimes drives this car

The first chart plots my mpg for each new refuel along with my current average. The second chart is just a bonus one, the distance for each refuel.

I’m averaging about 38 mpg on 9 data entries. So I am beating the highway mpg of 37.

What difference would there be if I did the more extreme hypermiling techniques?

Let’s do some basic math. Assuming I drive 10,000 miles a year and a cost of $2.50 a gallon, currently with 38mpg:

(2.50/38) x 10,000 = $658 in gas a year

If I did all the crazy reckless stuff I could very likely get around 43mpg:

(2.50/43) x 10,000 = $581 in gas a year

$658-$581 = $77 saving in gas a year; is it worth the risk? No. I like to enjoy driving too…even though I drive a boring car… but doing all those silly techniques would just be stressful for me. If you are someone that drafts behind trucks, please do it when you drive alone.

If you want to see the math behind this or see how to do it yourself check this article.

I’ll update this page every now and then with updated numbers.

Leave a Reply

Your email address will not be published. Required fields are marked *