Hypermiling – Techniques for Efficient Driving

I squeeze every mile out of gallon of gas in my cars to save some money and just because I can. I try some safe and somewhat unsafe hypermiling techniques of making my gas guzzling cars more efficient while trying not to be a victim of road rage.

Gas guzzlers

If you haven’t listened to my episode on Autocross, racing in parking lots, you should. Besides racing, I talk about my love for cars and a few of the cars I’ve owned, and why I gave up my German performance cars – they just cost too much to maintain and run, including how much gas they use.

My Mercedes, BMW, Mini Cooper, and even my Acura now all use premium gas. They use premium gas, a higher octane gas, because of how they’re designed. It’s not a matter of using “better” gas, it comes down to science and how the car is engineering to perform at its best, both performance and efficiency wise.

You can run regular or lower octane gas but you don’t end up saving any more money since the cars will end up using more gas. The cars will also pollute more so there’s that.

I didn’t even know some cars needed premium gas until I owned one. Then it was just another thing I had to pay more for to enjoy the cars.

Unfortunately, even getting a Japanese car like an Acura like I have now or a Lexus will not save you from having to buy premium gas. You cannot have a higher end, performance car without an engine designed to use high octane gas.

What you can do to ease the pain on your wallet is try hypermiling.

Hypermiling

Hypermiling, or energy-efficient driving, is basically a set of techniques to reduce your fuel consumption. Some are common and are actually good for your car and some are dangerous and illegal.

Hypermiling became a term and popular in the 2000s as gas prices shot up and energy-efficiency became more common place, and it became the word of the year in the Oxford dictionary in 2008. Hypermilers were motivated by a combination of being green and saving money. Hypermiling also coincides with the popularity of the Toyota Prius, the defect car of energy-efficiency minded drivers.

Thanks to the Internet, communities of milage geeks got together to share tips and tools, including electronic gauges to give live and average milage readouts, which are standard on cars now.

Like other hobbies I’ve talked about, competitions are an important part of the communities, including beating EPA mileage numbers for cars by 30 to 100 percent. For example a Kia rated for an average 26mpg can get 45mpg consistently.

“I’m trying to hit 50 mpgs,” Thaller said. “I don’t know if this car is capable of it, but I’m trying to get there. It all adds up. It’s kind of a game to get the tenths of a mile up there.” [https://www.denverpost.com/2008/07/08/hypermilers-stretch-their-gas-mileage/]

Unlike other car-related competitions, races weren’t to save time but to get the highest MPG numbers or the longest distance on one gas tank.

You can see how this could lead to some less safe and outright dangerous methods of saving gas. We’ll get to what some of those things are, but the Hypermiling Safety Foundation was created in 2008 to educate people looking to get into energy-efficient driving safely and legally.

When I heard that I could potentially get 30% more out of my gas tank just by changing how I drive a bit, I was sold.

Hypermiling Techniques

The first step to hypermiling successfully is being able to track your MPG in real time and over a trip. Otherwise, it’s hard to tell if what you’re doing is working and how well. Yes, you can record your total distance travelled divided by how much gas you put in your car, but that’s not precise enough.

I bought a bluetooth OBD2 adaptor on eBay and waited for it to come from China. OBD2 is the computer connection that’s in all cars since 1996 and what mechanics use to figure out why your check engine light is on. You can buy readers to do the same thing and you can buy bluetooth readers to hook them up to your phone to get the live readouts you need to figure out how efficiently you’re driving.

With my adapter and my iPhone mounted on my dash, I was ready to get started.

Maintenance

You’ve probably heard of the easiest technique of properly inflating your tires. There’s less friction because there’s less contact between your tires and the pavement. Start by making sure they’re inflated to what your car manual says. If you want to take it further, you an inflate them to the max inflation printed on your tire. You can get up to an increase of 6% MPG.I opted to fill my tires to their max.

Next, make sure your wheels are aligned properly otherwise you’re driving a car that’s like those shopping cars with one bad wheel – fighting it constantly to go straight.

Reducing Mass and improving Aerodynamics

You know how cyclists wear spandex and hug their impossibly light bikes to go as fast as possible? Cars work the same way – besides the shape of the car itself, accessories like roof racks product drag and make cars use more energy to move. Removing these can increase your MPG by up to 20%.

Once you’ve stripped your car of any accessories, it’s time to lose weight: the less your car weighs, the less energy it takes to move it. The easiest way to do this is to take all the junk out of your trunk, under your seats, and your door jams. For every 100lbs you lose, you’re looking at gaining 2% of MPG. By the way, the weight includes the driver and passengers, so try to make friends with gymnasts instead of football players.

I took everything except my spare tire out of my cars and I was usually the only one in my car so I didn’t have any one to kick out.

You can take this to an extreme by taking out your back seats and spare tire. I thought it would be strange to have a BMW with no rear seats and knew my luck wasn’t good enough to drive without a spare tire.

Finding an efficient speed

Cars have a sweet spot where they cruise – minimal throttle and the best gearing like when you find just the right pace biking where you’re moving fast and not getting tired. The most efficient speed vary from car to car but they are usually in the 50-80km/h range.

You can see the challenge this creates on slower streets where they’re 40km/h and on highways with their 100km/h speed limits. This is also a challenge when there is traffic – stop and go is the worst thing for efficiency.

I didn’t have much of a choice here, I couldn’t avoid rush hour traffic to and from work. I tried to find more efficient routes that took longer but where I wasn’t sitting as much. In the end, I opted to get home sooner rather than save a few dollars.

Accelerating and braking

Accelerating and braking efficiently is where you start to have an effect on other drivers and where I couldn’t bring myself to continually ruin people’s days. You can maximize your efficiency by accelerating and braking less. To do this, you accelerate quickly and coast and minimize your braking by leaving big gaps ahead of you. You can use cruise control if you find it hard to maintain a consistent speed.

Accelerating, braking, and accelerating again is typically the flow in traffic. If you have ever left big gaps in traffic, you know it drives people behind you crazy and other drivers see it as an invitation to get in front of you.

You an further increase your chances of a road rage incident by timing red lights: you slow down well ahead of the light and try to coast to it slowly so you don’t have to come to a full stop before it turns green. Accelerating from a full stop is less efficient than accelerating when you’re already moving.

When I tried this a few times, I could feel people behind me thinking or yelling “what is he doing?! Why is he stopping so early? I’m going to miss my turning light!”

Coasting

Coasting is where you use minimal energy and are still moving, and depending on how you coast, it may be illegal.

In a manual car, you can put it in neutral or ride the clutch. It’s like when you stop pedalling on your bike and cruise without burning any calories. This is illegal in most places because it doesn’t put you in a good position to control your car if you need to accelerate out of the way of something.

I admit I did put my manual Mini in neutral to coast to red lights because they were predictable and I could anticipate when they’d turn green to put it back into gear.

I couldn’t bring myself to take coasting to the extreme of turning my car off completely in neutral. This is a technique used by only the most die hard hypermilers.

Shutting off your engine

Shutting off your engine when you’re stopped is a safer way of using no gas when you’re at a long light. Turning your car off and on though does put more wear on your starter and can be annoying for people behind you if you’re constantly turning your car off and one.

But, this technique works so well that for the last decade car manufacturers have added auto-shutoff to their cars to improve their advertised MPG numbers. If you listen for it, when a high end car stops next to you at a light, you’ll hear them automatically shut off and turn back on when the driver accelerates.

I tried this a few times but the thought of replacing an expensive starter on my car scared me out of saving a few bucks a month.

Turning off your AC

Your AC adds a load up to 5hp so turning it off can save you some gas. Opening your windows increases drag so it actually slows you down, like running with a parachute attached to you. To this day, I feel a bit of efficiency anxiety when I turn on the AC.

Drafting

You still see people drafting behind 18 wheelers on the highway – the big trucks shield your car from the wind, meaning less drag for you and high MPG. To get the 20-40% efficiency gains, you have to be 10ft or closer to the truck, meaning you’re tailgating risking your life and a traffic ticket.

“It’s absolutely insane,” agrees Sgt. Tim Burrows of Toronto Police Traffic Services. “If you’re right behind a big truck, you can’t see what’s ahead so your reaction time is compromised when the truck driver slams on his brakes. There’s no margin for error.” [https://www.wheels.ca/news/hypermiling-the-extreme-way-to-save-gas/]

Body modifications

Besides removing things on and in your car, you can add things to reduce the drag and increase efficiency. You can add grille covers to the front of your car so that air doesn’t flow in and slow you down. This can lead to overheating, a problem I had anyways in my BMW and Mini, which left me stranded on the side of the highway more than once.

This technique works well enough that some car manufacturers added automatic grille opening and closing to their most efficient car models and others reducing their grille openings all together.

It’s a bit counter-intuitive but the rear of the car has an impact on how efficient a car is. A popular modification among elite hypermilers is by elongating the back of the car almost like a boat shape. It reduces the turbulence at the back reducing drag.

Speaking of turbulence, the wheels cause turbulence as well so adding wheel skirts to cover the rear wheels can help. Obviously adding them to the front won’t work since you have to turn. Honda and GM did add these to their early 2000s efficient cars.

To reduce the drag under your car, you can add a flat cover or tray. That is if your car already doesn’t have them. This is another feature manufacturers adopted and annoys me every time I try to change my oil and have to remove a bunch of plastic panels.

Hypermiling savings

Over the course of months, I tried the more aggressive techniques and tracked my MPG. While I did end up increasing my efficiency by 20-30%, it wasn’t worth the stress and concentration. I couldn’t even listen to music because I couldn’t focus on my RPMs, keep an eye on traffic, and try to time lights.

At the end of the day, saving $10-$20 a month was not worth the stress. It was like dieting where you count all your calories for a month only to get on the scale to see you’ve only lost 2 pounds.

The other realization I had was that I bought performance cars and was treating them like the tiny, efficient cars they weren’t. I had to remind myself why I bought them in the first place. Knowing that I wouldn’t keep them forever, or even longer than a year, I went back to enjoying driving them. To balance the money I spent on premium gas, I ended up biking to work regularly. Not only did I save money, but I was healthier and felt less guilty when I drove my cars like I stole them.

The simplest hypermiling tip that even the police support is simply driving the speed limit. In fact, during the gasoline crisis of the 70s in the States, speed limits were reduced to about 88km/h to increase efficiency and reduce the demand for gas.

It’s tough to do if you’re not used to doing it because 40km/h can feel like you’re moving backwards, but not only is it more efficient it’s also a lot safer in the event of an accident.


Hypermiling doesn’t seem as popular anymore. In the last 10 years, cars have become more efficient, hybrid sales have grown, and electrical cars have changed the efficiency game. It also came to an end for me after a few years.

I did enjoy the challenge and technology involved. I liked going down he rabbit hole on forums looking for charts to figure out the most efficient speeds for my cars. I did get caught up in tracking and monitoring my mileage stats and trying to improve them. I’m kind of a tracking addict. I track my bike rides to and from work and try to figure out where I can improve.

What I learned from tracking though is that it leads me to making dumb decisions, like coasting with my engine cut off or not stopping for stop signs on my bike and being called a “goof” by people waiting to cross.

I know myself now and I know that the few dollars saved was not worth it for me.