What is Hypermiling?

By Matt Keegan
Last Updated 05/07/2015

There is a group of people on the roads who seek to squeeze more miles out of a gallon of fuel than seems scientifically possible. Known as hypermilers, these individuals examine the EPA fuel ratings for their vehicles, and then find ways to beat those numbers by 5, 10 or 20 or more miles per gallon.

Hypermiling may seem like an off-beat way of driving, or it may be something that you are already embracing in a bid to save fuel. Let’s take a look at hypermiling and what it means for those who participate in this fuel-saving strategy.

Hypermiling Defined

Simply put, hypermiling is a process where car owners make adjustments to their vehicles or to their driving techniques (usually both) in an effort to maximize a vehicle’s fuel efficiency.

Such drivers typically operate their cars at lower speeds and engage in coasting to maximize their mileage. You should know that not every method here is safe and we aren’t endorsing the practice, but we are pointing out the strategies that some drivers employ to increase their gas mileage.

Enhance the Tires

You should never do anything with your tires to potentially harm them. Tires should always have sufficient tread and be inflated to the car manufacturer’s recommended pounds per square inch (PSI) rating when cold. Some drivers opt for low-rolling resistance tires, what can increase fuel economy, but may also can affect handling.

Some hypermilers like to attach wheel skirts to the rear wheels in a bid to better manage airflow, which is a method used to increase fuel efficiency. If you install skirts, ensure that they are securely fastened, otherwise they may fall off and litter the highway.

Kill Your Comfort

Serious hypermilers also resist using the air conditioning as they know that the climate control system is a drain on fuel efficiency. It is a comfort-killing method that can be brutal to employ on a warm day.

But keeping the A/C off isn’t enough — all windows must be tightly shut, otherwise, wind drag will adversely affect fuel economy. As you might imagine, this step is only for the truly dedicated people who can withstand intense heat and the odoriferous results.

Cruise and Speed Control

One of the best ways for all drivers to save on fuel is to activate the cruise control at highway speeds. However, you do not want to activate the cruise control when roads are wet as you may inadvertently cause your vehicle to spin.

Hypermilers, though, may not rely on cruise control as they prefer to be in control of the car’s speed at all times. On the highway you can see them in the right lane, typically going well below the speed limit and hugging the white line on the right side.

Where hills are involved, a hypermiler practitioner may build some momentum while climbing and then cut off the engine while moving down the hill, coasting his way along before restarting the engine. This step is possible only if the steering wheel doesn’t automatically lock when the engine is turned off.

Lighten the Load

If the previously mentioned tips are leaving you frowning, there are some other methods of achieving higher fuel mileage that may be more to your liking. Certainly, a number of hypermiler techniques seem extreme and some are not particularly safe.

For the rest of us, you can squeeze more miles out of a gallon of gasoline or diesel fuel by doing the following:

1. Empty your trunk. For every 100 pounds of stuff in your trunk or behind your back seat, your vehicle fuel economy will fall by about 1 percent. As you might imagine, smaller cars benefit more from removing junk than larger vehicles.

2. Remove your roof rack. If you carry anything on the roof of your car, wind drag will harm fuel economy, dropping it by as much as 25 percent according to the EPA. Hypermilers not only avoid this practice, but they are also likely to remove the roof racks. However, some don’t stop there. Hypermilers have been known to remove the back seat and anything else inside the vehicle that can save weight without compromising safety.

3. Idling is awful. Hypermilers live for green lights and will often time their driving to avoid stops of any kind. You can’t always avoid the lights, but if you are stopped at an intersection for more than a minute or are waiting for a freight train to pass, cut off your engine and you will save fuel.

4. Start slowing and avoid braking. You will kill your fuel mileage if you employ any number of aggressive driving techniques, including rapid acceleration, quick braking and speeding. Hypermilers essentially crawl away from a stop and gradually build to their intended speed. When it comes to braking, they often do so only when absolutely necessary, timing their driving to pass through synchronized green lights.

Hypermiler Considerations

Devout hypermilers also employ a number of other strategies to help them improve their fuel economy. On highways, some prefer to ride immediately behind an 18-wheeler, allowing the big rig to absorb wind drag. The problem here is that they ride too close to trucks and the rig driver is not able to see them in his mirrors. Practices like this create a safety issue that is best avoided.

Smart ways to save on fuel involve taking roads that are less traveled, taking advantage of tail winds and avoiding crosswinds and head winds. Taking to the road when the weather is warm, where traffic is light and when road conditions are favorable are other ways to save fuel. And if you have a GPS system, use it to avoid traffic delays, which can seriously hamper your fuel economy.