PHYSICS IS FUN! THE JOY OF EFFICIENT DRIVING

 While I used to think the best way to have fun driving was to head out to the track, I have been shocked to discover maximizing fuel efficiency can be just as fun!  Yes… FUN.  I know it sounds crazy, but hear me out.  In hopes of sharing what I have learned, I am writing this post to try ad inspire others to follow a similar path and learn how interesting and rewarding efficient driving can be.

     My revelation began about 3 years ago, when I bought my first hybrid.  As a fast-car lover, friends and family were surprised I went with the “efficient choice” instead of the “fast choice”. To be fair, the car was technically a sport-hybrid (Honda CR-Z), but that is beside the point.  The efficiency of the car was pretty good, but nothing amazing.  The true value this car offered was its role as a learning instrument.  It completely changed the way I drive, and has helped both my fuel efficiency and gas savings to sky rocket! 

     By upgrading to 2015 hybrid technology, the newest and most effective tool at my disposal was the mpg display.  This display both gave me an average mpg over a chosen distance AND an instantaneous display of how much gas was being used at the moment.  As monumental as the first speedometer or tachometer, this display grants the driver a deeper awareness into what the car is doing behind this complex machine is doing behind the scenes.  It encouraged me to maximize saving gas by enabling me to test different methods, then measure the efficiency result both in real-time and averaged over a set distance.  When I first bought the car I averaged the same efficiency as the EPA rating: 33/38 mpg in the city/on the highway.  Then, after a couple months of testing various techniques, I consistently produced an average of 42 mpg city and 53 mpg on the highway…. WOW!  Busting out the ol’ calculator, that is an efficiency increase of over 30%!  And I did not without modify the car at all, just my driving habits.  Now, I apply this understanding to ever vehicle I drive, both lowering carbon emissions and saving money simultaneously: WIN WIN. 

     For the first time, I am excited to put what I have learned done in writing and share it.  To put this driving mentality concisely: Maintain Momentum.  Momentum is at the heart of engine efficiency.  In short, engines are most efficient when maintaining a low speed and least efficient when increasing speed to make the car go faster.  Below are 8 Means of Efficiency.  In-depth, yet concise, I have included explanations to go with each one.

1)      ACCELERATE SLOWLY: Watch your engine speed (rpm) on the tachometer and try to keep within 2,000 to 3,000 rpm while accelerating. At mid engine speed the engine gets the most power for the least gas.  At low engine speed there is a lot of friction to overcome and at high engine speed the heat becomes a problem.

2)      BRAKE RARELY:  Braking is the enemy of efficiency.  According to Sir Isaac Newton, “an object in motion stays in motion”, requiring energy to change speed.  All the energy put into moving cars is wasted when we slow ourselves back down.  Luckily hybrids and electric vehicles can capture some of that braking energy through regenerative braking.  This is where an electric generator creates electricity using the wheels’ rotation, then storing it on the battery while slowing down the car.  However, it is not a perfect system and braking should be avoided by everyone, as often as possible.  Just make sure to still put safety first!

3)      BRAKE EARLY: When you do need to slow down, start braking early.  Most events we slow down for are temporary and often clear-up quickly.  For example, when a light turns green and traffic takes time to get moving, it only takes a few seconds for it to get up to speed.  The longer it takes for you to get to that traffic, the faster it will be when you reach it.

4)      COAST OFTEN:  Once you get up to speed, do your best to stay there, gently adding just enough gas to keep you going.  When you might need to stop, start slowing down from a distance by letting off the gas and using air resistance.  Gentle is the key word for maintaining momentum.  Imagine carrying a cup of coffee on your dashboard and trying to not spill a drop.

5)      USE HILLS:  Hills are simultaneously amazing and horrible.  While climbing hills requires a lot of speed and kinetic energy, potential energy is being built up in your vehicle the whole ride up.  Coming down the other side then unleashes the energy again and returns the speed.  To take advantage of this, use the least amount of gas as needed to get up a hill, slowing down as you climb, just like a semi-truck.  This will store your power as potential energy.  Then, use the downhill slope to regain the energy the energy as speed, barely using gas, while allowing gravity to do the work.

6)      WATCH TRAFFIC:  It is a good practice to constantly be aware of the traffic around you.  If you can anticipate future braking, you can act now to avoid it.  For example, someone turning several cars ahead of you, will likely slow you down, but if you are aware, you can change lanes ahead of time.  Another example is on the freeway, when brake lights are visible far ahead of you, brake early and potentially arrive as the braking is clearing up.  If you see traffic is completely stopped, for something like an accident, you could potentially exit early to avoid it.  Being aware of your surroundings will increase your ability to choose.

7)      WORK WITH TRAFFIC LIGHTS:  Many traffic lights are set up to get operate as efficiently as possible.  Most use timers that are programmed match the flow of traffic.  These timers are usually modeled around a car averaging the speed limit.  To try and minimize stops at red lights, drive the speed limit.  You will theoretically get all greens along one street.  Some lights are timed differently than others, so you may need to go slightly slower or faster depending on the street.  Once you learn a street’s system, it should always work as long as the timing doesn’t change.  Some streets with timed lights I use regularly are Montgomery, Wyoming, Lead, and Coal.  If you get with the main flow of traffic on these lights, and generally stay the speed limit, they will consistently have green lights, allowing smooth, steady, and efficient travel.

8)      GREEN INDICATORS:  As you approach a red light, there are indicators that tell you when it will switch to green.  A common one to watch for is what oncoming traffic is doing.  If it is stopped at the light, then your light will likely stay red for a while longer, but if it moves through the intersection, your light will likely get the green soon as well.  Another indicator is surprisingly simple.  Sometimes the perpendicular green light of an intersection is visible as you approach a red light.  Seeing it turn yellow, then red, is a sure way to know your light is about to become green.  Knowing how long your red will last can help you better regulate your driving in time with the light and likely increase your efficiency.

     Each of these methods can be optimized and added to; these are some base ideas.  If anyone reading this has anything to add, has questions, or just wants to geek-out about the joy and reward of efficient driving, feel free to contact me here at Vibrantcy!

Trevor Keegan