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In truth,
the ideas and images in men's minds are
the invisible powers that constantly govern them.
--John Locke
 The XR3 Hybrid is a super-fuel-efficient two-passenger plug-in hybrid that achieves 125 mpg on diesel power alone, 225 mpg on combined diesel and electric power, and performance like a conventional automobile. The design of the XR3 Hybrid focuses on existing technologies and a vehicle “personality” that makes conserving energy a fun driving experience. It showcases the design ideas explored in Robert Q. Riley’s book, Alternative Cars in the 21st Century.
At just 1480 pounds, this high-performance design combines fast acceleration, a maximum speed of 80 mph, and fuel economy of 125- to over 200-mpg.
Its clam-shell canopy and three-wheel platform boldly differentiates the XR3 from conventional passenger cars. The vehicle’s hybrid power system, diesel engine, and low curb weight are the main ingredients of its super-high fuel economy and excellent performance. Acceleration equal to that of a conventional car and a maximum speed of 80 mph make the XR3 Hybrid equally at home on freeways and surface streets.
Plans enable people with common building skills to build a duplicate of the XR3 Hybrid prototype or convert their own car into a significantly more fuel-efficient vehicle. Readers will understand the factors that influence fuel economy, and learn how to make any car achieve greater fuel economy. The XR3 Hybrid gives enthusiasts and experimenters the opportunity to significantly reduce their transportation expenses and have fun doing it. On a broader level, the vehicle is a highly visible example of the kinds of vehicles that could help reduce personal mobility energy.
Styling Makes an
Implied Promise
The driving experience is defined by the vehicle’s layout and styling – it's “theme" or "personality.” The vehicle theme says: “This is what I am and this is what I do." It’s a statement that’s on a visual level, and it’s maintained throughout the ambiance of the vehicle. Mechanical design simply supports that statement. “Once we decide on the basic architecture of the vehicle, styling is the first thing that’s done,” says Riley. “It’s the most intangible quality of the design, but it provides a visual marker for what we are trying to achieve through mechanical design. Styling makes an implied promise, and then it’s up to the mechanical designers to deliver on that promise.”
The Technology of
Fuel Economy
The vehicle’s performance and fuel economy comes from a combination of two fundamental design factors. First, it’s essential to keep the vehicle as light as possible in order to reduce the amount of mechanical "work" that has to be done. The method of getting rid of unwanted mass while still keeping the car’s mechanical benefits demands good design and modern materials. Once the amount of "work" has been minimized, then the other part of the equation is to do the remaining "work" as efficiently as possible. And that’s where the hybrid power system comes in. So the fundamental approach is very simple. The key is in the execution.
Consumer Perceptions and Choices
Everyone understands that small, super-efficient cars would help the environment and reduce imported oil. But industry has been slow to see marketing opportunities and create products of this category that capture the imagination of consumers. The XR-3 Hybrid is designed to explore vehicle packaging and styling, with an eye toward creating a new design theme and market positioning for alternative personal transportation products. We call it a “Personal Mobility Vehicle.”
To paraphrase the lead quote from John Locke, the ideas and images in the minds of designers invisibly guide them toward particular design options. A product’s “character” naturally emerges from the collective mind-set of its designers. Consumer appeal of any alternative mobility product depends on the ideas and images in the minds of its creators, not on the core idea of saving energy and emissions through size/mass reduction. In order to enjoy success in a consumer market, significantly different vehicle types - Personal Mobility Vehicles - must be rendered in ways that create new appeals of their own. And energy savings and emissions reduction must be positioned as secondary benefits. Or stated differently, a consumer vehicle’s environmental benefits can be an effective motivator only in terms of providing a rationale for a purchase that is, in fact, based largely on the product’s emotional appeal.
The XR3 focuses on the power of “design” to influence consumer perceptions and choices. It points to a new category of personal mobility products that are neither automobiles nor motorcycles. The XR3 is more than just a build-it-yourself vehicle. It’s a design statement, and its success with consumers is likely to influence the designs and product lines coming from the world’s carmakers.
Plug-In Hybrid Architecture
The XR3 is a “plug-in hybrid.” This makes it possible to drive on battery power alone on trips of about 40 miles. And when both the diesel and the battery-electric systems are used together, and the car is driven conservatively, fuel economy increases to over 200-mpg. Fuel economy is about 125-mpg on diesel power alone.
Today’s hybrids are called “mild hybrids” or “charge-maintaining hybrids”. They use the electric system to help with acceleration. You can drive on battery power alone, but only for a short distance – around the block, for example. The battery pack is typically used to provide bursts of power for brief periods of acceleration. The combustion engine then recharges the battery between periods of acceleration. But fuel economy suffers while the battery is being recharged. That’s why today’s hybrids do not provide much advantage in fuel economy over a well-designed conventional car.
In order to get the full benefits of a hybrid power system, you have to switch to the plug-in hybrid architecture. Plug-ins will be the next generation of hybrid vehicles. A plug-in hybrid simply means that part or all of the vehicle’s energy is taken from the grid system where it is cleaner and less costly to produce. Most of the world’s automakers are now working on plug-in hybrids.
Virtually Unlimited
Options for the Builder
The plug-in power system architecture also allows much greater flexibility in power system choices. With a mild hybrid, like the Honda Insight and the Toyota Prius (also called “charge-maintaining hybrids”), proper control of the power system depends on the fact that the subsystems - the internal combustion engine (ICE) and electric systems - are selected in advance and controlled by a computer. The computer, however, has to be programmed for the specific output characteristics of the two systems. Any modification in either of the power systems (electric or ICE) can cause a mismatch with the control system. So whenever a change is made, the computer has to be reprogrammed.
With the XR3, the two front wheels are powered by the combustion engine, and the single rear wheel is electric powered. The two power systems are not integrated within the vehicle. The connection between the conventional power system and the electric power system is provided by the ground. Proper phase-in between the two power systems is handled by a simple throttle mechanism and a dash-mounted switch to select between ICE power, electric power, and dual power modes. In the dual power mode, the XR3 will have lots of burst power for quick acceleration. If you were to use this acceleration potential to its fullest, fuel economy would be reduced to something on the order of 150 mpg over a 70 mile trip. Fuel economy will also vary according the particular components chosen for the power system, and how heavy you are on the throttle pedal. Performance figures quoted here are conservatively-driven vehicle having a system configured just like the prototype. Plans provide the information necessary for you to select different components if you want to.
Removable Front Clip & Canopy
The canopy and the entire front of the body are removable. Removing the front body section provides complete access to engine and suspension components for major servicing.
This removable front clip can be restyled and extended to provide additional forward space for a more powerful engine. With a larger engine you can have big-engine performance and still retain the ability to run on battery power alone. The existing 65-pound (29.5 kg) transmission will handle up to 300 horsepower (223 kW).
The removable canopy provides another level of freedom. A different windshield can be installed to create an open-air roadster effect.
Safety Features
The front portion of the front clip is foam-filled to absorb low-speed frontal impacts. It also serves as an easily replaceable sacrificial element in the event of a frontal collision. The sides of the vehicle are filled with foam to provide side intrusion protection. This foam-filled region, varying in thickness from 5 inches to more than 10 inches, extends from the front wheel wells to the rear bulkhead of the passenger zone, and vertically from the canopy parting line to the bottom of the passenger zone. The design is significantly more resistant to side intrusion than the doors of conventional cars.
A composite roll bar is built into the perimeter of the panel that defines the rear of the passenger zone. In addition, the canopy is equipped with a tubular steel perimeter frame which is reinforced by steel “A” pillar members. This provides excellent rollover protection.
An open interior having no conventional instrument panel or steering column provides forward excursion space for occupant deceleration during a frontal collision. Controlled deceleration is provided by conventional seat belts.
There is no conventional steering column. The steering wheel is supported from the side. The supporting structure is designed to break away in a frontal collision. It is not designed to resist/carry the loads that would typically be imposed by the forward excursion of the driver.
(During a frontal collision, air bags prevent occupants from impacting the interior of the vehicle. Air bags are unnecessary in the absence of nearby interior structures that may be impacted by forward excursion of occupants.)
Construction Costs
Construction costs are highly variable because of the many choices available due to the XR3’s design. It’s a modular design that lets builders make choices according to their budget and performance goals. More than half the cost of parts for the XR3 prototype went to the electric propulsion system. In other words, the cost of electric propulsion components is greater than the cost to build the entire remainder of the vehicle, including the diesel power train.
At the upper limit, a duplicate of our Li-Ion-powered prototype will top $25,000. If you switch to lead-acid batteries, you can save the difference in cost between the two types of battery systems. Li-Ion batteries in the prototype cost about $7,500 ($9,000 delivered with a battery management module) and a lead-acid battery pack will cost between $1,500 and $2,000.
At the bottom end of the scale, a diesel-only vehicle capable of achieving 125-mpg can be built for less than $10,000. And the modularity of the design allows you to begin with a diesel-only vehicle then add the electric power train components later on. Nothing in the power train has to be changed. It’s simply a matter of leaving off the unwanted components. You can, however, enlarge the 3-gallon fuel tank to 9 gallons and end up with a range of over 1,000 miles on a single fill-up.
Similar options are available with a battery-only vehicle. One can simply leave off the combustion power system, install more batteries in the extra space, and end up with a BEV capable of driving 100 miles on a charge. Li-ion batteries can be recharged in about two-hours.
These cost-related choices also affect the performance of the vehicle. For example, leaving off the electric propulsion system reduces vehicle weight from nearly 1500 pounds to about 950 pounds. This improves diesel-only fuel economy and acceleration. When the electric propulsion system is not installed, the engine is then loaded to only about 41 pounds per horsepower.
Plans
The XR-3 Standard Plans Package is $170. The package includes eighteen D-size (24 x 36 inch) drawing sheets, one 32 x 64 inch full-size template sheet, and a 149-page construction/technical manual with over 200 photos and illustrations.
The XR-3 Deluxe Plans Package
is $200. The Deluxe version includes everything from the Standard version plus two CD-ROMs and one DVD.
One of the CD-ROMs contains SolidWorks 2D CAD drawings and 3D models, along with DXF files necessary for water-jet or laser cutting flat metal parts. The DXF files alone will save many times the extra $30 because your water-jet or laser service does not have to create the necessary files from drawings. (DXF files provide tool-path information for automatic processes.) The second CD-ROM contains a construction manual set up to run in a web browser with click-to-enlarge high-resolution color photos, video clips, and SolidWorks eDrawings 2D drawings and 3D models. You can get a free viewer that will let you view and take dimensions from the electronic CAD files and 3D Models.
The DVD contains over one hour of video of the vehicle being built. It’s a “reality TV” show, not a Hollywood production. The two prototyping technicians who built the XR3 had no prior experience with fiberglass. So the video includes minimally-edited clips taken at various stages of construction along with verbal instructions and comments on the particular operation.
When you purchase plans you will be automatically subscribed to a password-protected update site. Your user name and password will be emailed to you when your plans are shipped. You will receive periodic notifications of updates when new content has been added to the update site. You can unsubscribe at any time, but the update site lets you stay informed on the latest developments and improvements to the XR3 Hybrid plans. New information that will be added includes: additional computer files, new drawings and photographs, new techniques for building, and new resources and vendors.
If you’d like to try the eDrawings
viewer, you can download an executable eDrawings file (in a zipped packet) of the
Front Wheel
and Knuckle Assembly model (4.80 MB) by clicking on the foregoing
link. You have the option to either Run or Save the file.
Kits
Although the XR-3 can be built just as the prototype was built, kits are on the agenda. Information will appear on this page as it becomes available. But the XR3 can be constructed using the same techniques used to build Tri-Magnum. Click on
FRP/foam composite for a document that shows the composite system used to build the body for the XR3.
A knocked-down body kit consisting of pre-molded panels provides the greatest benefit at the least cost. So body kits will be supplied as unassembled panels that builders can bond together. In addition to enabling the lowest price, this type of kit also reduces packaging and shipping costs. Frame kits will consist of a welded-together assembly, which turns the project into mostly a bolt-together operation. The goal is to deliver the greatest benefit at the lowest possible price, and avoid supplying parts that you can purchase locally.
The price of kits has not
been established.
Completed Vehicles
Information not available at this time.
About the Designer
Robert Q. Riley consults for corporate and private clients on new
product design and product strategies. He promotes environmentally
friendly technologies, and writes and speaks on the subject of
alternative automobile design. He has chaired conference workshops and
spoken at industry, scientific, and academic events, including the
Global Energy Future symposium (Columbia University), the World Car
Conference, and the Northwest Alternative Fuels Conference. He consulted
on the Different Roads automobile exhibit at New York’s Museum of
Modern Art, and was a panelist on the museum’s daylong symposium on the
future of the automobile. He was one of the two U.S. technical
consultants selected by Delcan Corporation to assist with Transport
Canada’s Sustainable Transportation Technology Forecast.
Mr. Riley is the author
of
Alternative Cars in the 21st Century: A New Personal Transportation
Paradigm (Society of Automotive Engineers, 1994 & 2003), and Alternative
Fuels for Spark-Ignition Engines (for a volume on Motor Gasoline
in the series, Critical Reports on Applied Chemistry, Royal
Society of Chemistry & Society of Chemical Industry, U.K., 1995). The
Second Edition of
Alternative Cars in the 21st Century, with a
Forward by Dr. Paul MacCready, was published in 2003.
Specifications
| Seating |
Two,
side-by-side |
| Wheelbase |
88 inch |
| Track: |
66 inch |
| Curb Weight |
1480 lb |
| Height |
43 inch |
| Engine |
Kubota D902
tractor engine |
| Motor |
Advanced DC
8-inch motor |
| Transmission |
VW Type 1 |
In
the News
Automotive Manufacturer China magazine ad - distributed at the 2008
Beijing Auto Show, April 20th-28th, 2008:
XR3 Hybrid Ad
Rich
Ruggles, owner and Webmaster of the site, Fuel Efficient Vehicles
Now!, has applied powerful vehicle performance analysis tools to the
XR-3 Hybrid. The result is a very informative technical analysis that
shows the effect of various power train options. You can access the
overview and performance graphs at:
XR-3 Hybrid.
Podcast on 08/11/2008 by EVCAST
Report on 08/07/2008 by Greentechmedia
Television Report on
06/17/2008
Television Report on
03/30/2007
Television Report on
03/27/2007
News Release on 03/20/2007
Report by
Arizona Republic
Report by
MSNBC
Report by
Arizona
Reporter
Report by
Serious Wheels
Report by
AutoblogGreen
Report by
Forbes
Report by
Mobile Magazine
Report by Gizmag
Report by
Gizmodo
Report by
The Auto Parts Geek
Report by
Technoride
Report by
Channel 4
Report by
TreeHugger
Report by
Fuel-Efficient Vehicles Now!
Report by
Green Car Congress
Report by
Inside Line
Report by
Jalopnik
Report by
The Auto Channel
Report by
BusinessWeek
Report by
HorsePowerSports
Report by
Motorcites
A PowerPoint
presentation by Robert Q. Riley, October 26, 2006, for the American Society of
Mechanical Engineering (ASME) students at Arizona State University. For
best results, save file, then open in PowerPoint.
A PowerPoint
presentation by Robert Q. Riley, October
11, 2007, for the Center for Advanced Vehicular Systems staff at
Mississippi State University. Click on the link above to be able to OPEN
or SAVE the presentation.
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18 D-size drawings
