Honda Insight: Hybrid gasoline-electric car by Will Ryu Why SUVs don't get good fuel efficiency. In general there are three important design considerations in building any type of fuel-efficient vehicle: low aerodynamic drag, low weight, and low rolling resistance. Relative to a conventional car, the Insight achieves all three of these design goals. At high speed most of the engine's power goes into pushing air out of the car's way. Or to put it another way, on the highway, typically 1/2 of the power loss is due to aerodynamic drag for a traditional car. It goes without saying that reduction of drag is a big part of fuel-efficient car design. With a 0.25 cd, the Insight has the lowest aerodynamic drag coefficient of any commercially mass-produced automobile. For comparison my VW GTI-VR6 has a 0.35 cd, and the Ford Explorer has a 0.42 cd. So if the Insight's tear drop shape looks a little odd to you, just remember that the goal of aerodynamic efficiency dominated the exterior design. The small front profile works with the low drag coefficient to reduce the load on the car at high speeds. The rear wheel wells have plastic skirts that allow the airstream to move smoothly past the tires, instead of becoming turbulent. The rear underbody has plastic panels to smooth the airflow beneath the car. Aluminum alloy frame The aluminum frame construction technology has trickled down from Honda's experience building the aluminum body Acura-NSX. In addition to the frame, most of the major body panels of the Insight are also made of aluminum. Honda's use of aluminum construction makes for a very light car (about 1800 lbs). For comparison my VW, a small 3-door hatchback with a steel frame weighs over 2800 lbs, and a Ford Explorer weighs about 4000 lbs. The Insight's single body aluminum frame is 47 percent lighter than a comparable steel body yet it has better bending and torsional rigidity. In addition to the frame, the car's front and rear suspension arms, and even the front brake pad calipers and rear brake drums are made of aluminum as well. The gasoline engine itself weighs just 124 pounds. Finally, a bunch of nickel-and-dime weight-saving features are located throughout the car, such as the plastic-resin gas tank, the magnesium alloy oil pan, lightweight 5-speed transmission, and lightweight exhaust. If you place a car on a level surface, put it in neutral, and try to push it so it moves at a slow but constant speed, you will find that it takes some force to do so. This is because the car has rolling resistance, which is caused primarily from the energy lost in the tires due to the compression of the rubber. As a general rule, the harder the tires, the lower the rolling resistance. Unfortunately the trade-off of using hard tires is traction and cornering ability. So here Honda had to make a concession. They gave up some drivability for fuel efficiency by choosing special low rolling resistance tires from Bridgestone. It's a good compromise. Honda could have gotten even lower rolling resistance by using hard, narrow, plastic tires but then the car probably would have handled like a Big Wheel. Interior and Electronic Instrument Display The interior is a bit utilitarian - think mid-level Honda Civic. Spartan but functional would be my take, but style is a personal matter so check out the pictures above to come to your own decision. Instrument display Note the embarrassingly low 32.4 mpg reading in the lower center. Why so low? Because I took this picture after racing my friend in his Insight with my GTI-VR6 through Cambridge and Watertown. Let's just say, he needed to burn some extra gas to try and keep up with me, Heh heh. His lifetime average is about 60 mpg. I prefer analog gauges over digital displays, but the Insight's electronic display is well laid out and easy to read. This is important because you will be looking down at the display more often than in a conventional car. Arrows prompt you to up or down shift, presumably helping you achieve the best gas mileage. Tach on the left, and mph placed smack in the center. The mpg reading is prominently displayed in the lower center of the display and is continually updated. Once you start checking the mpg you're getting, it's hard to stop. Keeping your mpg reading high becomes an addictive preoccupation. Next: real world performance