FAQs ∨

RMI and MOVE

What does MOVE do?
How is MOVE related to Rocky Mountain Institute?
What is Rocky Mountain Institute?
How can I work for RMI?

The Hypercar®

What is a Hypercar® vehicle?
Can I buy a Hypercar®?

Design and Energy Efficiency

What are the best ways to make cars and trucks more fuel-efficient?
How can you design a better road vehicle?
What are the basics of ultralight vehicle construction?
How can advanced aerodynamic design save energy?
Can more efficient vehicle accessories save fuel?
What advantages does a hybrid car have?
How do I get the best performance out of a hybrid car?
What is Regenerative Braking?

RMI and MOVE

What does MOVE do?
MOVE is RMI’s transportation innovation group, leading cutting edge research and transformative industry engagements in the transportation sector. To learn more about the specific markets we work in, see Markets in Motion.  To learn about more on our Capabilities.  For more general information about MOVE, click here.

How is MOVE related to Rocky Mountain Institute?
MOVE is one of three research and consulting teams at Rocky Mountain Institute. The other teams are Built Environment Team and Energy and Resources Team.

What is Rocky Mountain Institute?
Rocky Mountain institute (RMI) has been working on solutions to our energy and resources issues for more than 25 years.  RMI is engaged in cutting-edge research on oil independence, renewable energy technologies, distributed energy, and resource planning.  Our innovations have profoundly influenced the energy sector, helped corporations to change how they do business, and pushed governments to adopt key enabling policy reforms.  RMI’s areas of expertise include energy use and supply, buildings and land development, transportation, manufacturing, and community economic development.  For more on RMI, click here, or visit rmi.org

How can I work for RMI?
RMI works with leading companies to rethink their products, processes, organization structures, and strategies. Many of our staff members are well-accomplished scientists with expertise in engineering, physics, architecture, and more. If you would like to see what positions RMI is currently trying to fill and the qualifications necessary to apply, please see our Jobs at RMI website. RMI also maintains a robust internship program for recent graduates and those with less experience than our full-time staff. Please see our currently available Internships if you would like to learn more.

We also list jobs specific to the MOVE team on our careers page.

The Hypercar®

What is a Hypercar® vehicle?
A Hypercar® vehicle is designed to capture the synergies of: ultralight construction; low-drag design; hybrid-electric drive; and, efficient accessories.

RMI's research has shown that the best (possibly, the only) way to achieve this is by building an aerodynamic vehicle body using advanced composite materials and powering it with an efficient hybrid-electric drive-train.

Unlike other efficient vehicles, Hypercar® vehicles don't compromise performance, comfort, or safety. These vehicles could profitably reduce carbon-dioxide emissions by two-thirds, partly by accelerating the shift to hydrogen fuel cells.

In 1994 we founded the Hypercar Center® to research and promote this concept. Having proved its technical feasibility through rigorous technical modeling, the Center's staff spent the past several years making Hypercar® technology a commercial reality. Their unconventional approach has been to place the concept in the public domain and share it conspicuously with some two dozen major car companies and new market entrants to maximize competition in capturing its market and manufacturing advantages. The result: billions of dollars' private investment, and rapid movement of Hypercar-like concepts toward the marketplace.

In 1999, we took this process a step further by launching a for-profit venture, Hypercar, Inc., to speed the industry's transition by exerting direct competitive pressure. This independent company, in which RMI has a minority interest, is now taking the lead in advancing key areas of Hypercar research and development.

In 2004, Hypercar, Inc. changed its name to Fiberforge (www.fiberforge.com) to better reflect the company's new direction and its goal of lowering the cost of high-volume advanced-composite structures.


Can I buy a Hypercar®?
Unfortunately, there is no Hypercar® readily available for public purchase. The Hypercar® concept was developed by RMI in the 1990s and the idea was then presented to several major automobile manufacturers to maximize competitive advantage surrounding the concept. In 1999 the Hypercar® project spun off into a for-profit venture, Hypercar, Inc., which was later renamed Fiberforge. They have developed some key Hypercar® concepts, such as vehicle lightweighting using carbon fiber and composite materials. For further information about the Hypercar® chronology and details of the design, please visit www.hypercar.com. For more information on Fiberforge, please visit www.fiberforge.com.

Design and Energy Efficiency

What are the best ways to make cars and trucks more fuel-efficient?
Making cars and trucks more efficient is a matter of minimizing energy losses. Computer modeling and research of technical developments by RMI’s MOVE team suggest that the best way to do this is through a combination of lightweighting, aerodynamics, hybrid-electric technology and efficient accessories.

How can you design a better road vehicle?
In recent years there have been dramatic advances in many related fields: materials, microelectronics, software, motors, electricity-storage devices, fuel cells. Integrating these advances into automobiles offers exciting new possibilities. But to exploit them fully requires new ways of thinking about automotive design.

Making cars more efficient is a matter of minimizing energy losses. Computer modeling and research of technical developments by RMI's transportation research staff suggests that the best way to do this is through a combination of:

Separately, these features have both advantages and drawbacks. But combining all of them in a whole-system approach captures impressive synergies, multiplying the benefits and overcoming the disadvantages. The results is vehicles that are 3–5 fold more fuel-efficient than comparable current models, yet are as good or better in every other respect.

What are the basics of ultralight vehicle construction?
Assuming an engine/drivesystem efficiency of 15–20 percent, it takes five to seven units of fuel energy to deliver one unit of energy to the wheels of a conventional car. Turning this around by saving energy at the wheels offers immensely amplified savings at the fuel tank. That's why the Hypercar® concept starts with ultralight, low-drag design.

Making the car lighter reduces both rolling resistance and the amount of power (and therefore fuel) needed for acceleration and hill-climbing. For the driver, that means a nimble car that's peppier and/or more fuel-efficient to drive.

The single biggest opportunity for making the car lighter is to replace much of the steel in the body and chassis with new materials such as Advanced Composites (and in some cases light metals). This allows other components — such as the engine and transmission — to be made smaller and lighter (since they don't have to transfer as much power to the wheels to carry an otherwise heavy body and chassis), not to mention less expensive. These mass reductions in turn allow the car's suspension to be even lighter (and less expensive) because it doesn't have to support as heavy a body, engine, transmission, and so on. This principle is called "mass decompounding."

How can advanced aerodynamic design save energy?
Today's cars are already fairly sleek, but aerodynamic drag can be further cut by 40–50 percent or more through low-angle windshields, a smooth underbody, a tapered rear end, minimized body seams, and aerodynamically designed air intakes, suspension, and wheel wells. These improvements could be achieved without overly restricting the stylist's freedom to make attractive and distinctive-looking cars. Large improvements could be made by just smoothing the underbody, which is essentially invisible.

Much of the scope for reducing aerodynamic drag is in smoothing the underbody.

Rolling resistance can be reduced by more than 50 percent, thanks not only to ultralight design but also the use of special (but not exotic) tires, wheel bearing assemblies, and brakes. These changes would be mostly transparent to the driver, since low-rolling-resistance tires and suspension systems can be designed to provide traction, comfort, and durability comparable to conventional ones.

Can more efficient vehicle accessories save fuel?
Currently, little attention is paid to reducing vehicles' heating and cooling "loads" (power requirements) or making their accessories energy-efficient. But in a Hypercar® vehicle, where the power needed for propulsion is so low, standard accessory loads would become an important part of total power consumption. Through careful choice and integration of efficient components, however, these loads could be reduced to about one-fourth of the current average, while providing equivalent or better functions.

Air conditioning is the single biggest load by far, so the first order of business is to ensure that the cabin doesn't get hot in the first place: insulation, special heat-reflecting (but visually clear) glass, solar-powered vent fans, and other design improvements can keep out most of the unwanted heat. Innovative cooling and dehumidification systems, run not directly by the engine but by its waste heat, can handle the rest. The same design improvements can minimize heating and ventilation loads, too.

Other loads can be reduced with new kinds of headlights and taillights (which shine brighter on a third the energy) and the use of fiber optics to illuminate the cabin and control panels with a single low-power lamp located outside the passenger compartment. Entertainment and other electronics can be designed for maximum efficiency as well.

What advantages does a hybrid car have?
A "hybrid-electric" drive-system offers several advantages over conventional systems.

Most importantly, the engine needs to handle only the maximum continuous load, not the peak load. Unlike the mechanical torque generated by a conventional system, the hybrid's electricity can be stored temporarily in a small battery or other similar device until it's needed for extra acceleration. Result: the engine can shrink to a fraction of the current normal size, reducing weight, cost, and fuel consumption; and it can always run at or very near its "sweet spot," typically doubling drivesystem efficiency. It can even turn off automatically whenever it's not needed.

Additionally, the electric motors of a hybrid vehicle can recover part of the braking energy that would otherwise be lost as heat in the brakes. They become generators, slowing the vehicle by using its kinetic energy to make electricity that is stored until needed. Some experimental vehicles have demonstrated up to 70-percent peak energy recovery, but recovery of about 50 percent is seen by many experts as a more realistic goal.

And finally, hybrid-electric drive opens the door to other exciting new electrical power sources, such as fuel cells.

The exact workings of hybrid drivesystems vary. There are two basic configurations: parallel and series. For more details on these, see the Hybrid Vehicle Propulsion Program On-Line Resource Center.

Many auto manufacturers are now developing or selling hybrid-electric cars, which is a huge leap forward in its own right. However, thanks to the principle of mass decompounding, hybrid-electric drive works better and costs less if you reduce the vehicle's weight and drag first.

How do I get the best performance out of a hybrid car?
To get a state-of-the-art 4-/5-seat hybrid-electric midsize sedan to perform at ~53–55 mpg (it’s rated at 55) rather than in the low 40s, it needs “pulse driving,” which differs in two ways from our old driving habits:

Note: Many reviewers test hybrids driven in the same way as non-hybrids, then gripe that hybrids fall short of their rated efficiency by more than non-hybrids do. This is incorrect; properly driven hybrids can actually match their EPA-rated mpg more closely than non-hybrids can. (A Honda Insight mild hybrid, for example, averages 63 mpg and is rated 64, the difference being more than attributable to snow tires; Toyota’s U.S. Executive Engineer, Dave Hermance, gets 53–55 mpg on his 55-mpg-rated Prius.) Consumer Reports is a major source of this confusion, having repeatedly refused to print a correction explaining that its standardized test procedure disproportionately reduces the mpg of the hybrids it tests. CR also calculates combined city-highway mpg differently than EPA and automakers do.

Consistent with attentive driving, you’ll also find it very instructive, when driving a hybrid, to keep an eye on the real-time mpg display and (like a videogame) use the feedback to improve your driving habits for best mpg.

What is Regenerative Braking?
When you hit the brakes, the car's kinetic energy is converted to heat through friction—throwing away the energy that was previously used to accelerate the car. In city driving, about 30 percent of a typical car's engine output is lost to braking. This proportion drops to almost zero in highway driving, where braking is much less frequent.

Have you ever followed a large truck down a long hill and smelled the acrid smoke from overheated brakes?

The heat that causes parts of a truck's brake system to melt and create smoke comes from friction. Traditional brake systems grip metal disks or drums, using friction to slow or stop the rotating wheels of a vehicle. The friction of the brakes resists the forward momentum of the whole vehicle, and that friction creates heat.

In order for something to heat up it takes energy. The energy that heats up a truck's brake system comes from its momentum, speed, and mass. Where does a truck's momentum come from? It comes from fuel. Traditional brake systems, like those on large trucks, waste energy by converting forward momentum into heat.

One of the energy efficiency advantages of hybrid-electric technology over traditional drivetrains is regenerative braking.

A hybrid-electric vehicle uses an electric motor to create torque to drive its wheels. Interestingly, electric motors can be designed to be virtually identical to electric generators. This means an electric motor can either use electricity to create torque, or reverse the process to use torque to create electricity.

This "reversability" of electric motors is very different from the internal combustion motors in most cars. Can you imagine turning the wheels of a typical car backwards and having gasoline pour into the tank? Essentially this is what happens when you put your foot on the brake of a Toyota Prius or Honda Insight hybrid-electric vehicle.

When a hybrid-electric vehicle is approaching a stop light, it does not create friction and useless heat in order to slow down. Instead it reverses its electric motor turning it into an electric generator, creating electricity which is fed back into a battery and stored for when the light turns green. In fact any time a hybrid-electric vehicle slows down, lifting the accelerator or application of the "brake" causes the system to use the vehicle's momentum to generate electricity.

Hybrid-electric vehicles with regenerative braking can save a great deal of energy when compared to traditional cars, especially in "stop-and-go" driving situations. 

If your inquiry is not addressed on this FAQ page, please contact an RMI/MOVE staff member.