Huge gains in transportation efficiency have been available but people must want them and use them

Brad Templeton points out the benefits of half width cars and lighter robotic cars. I agree that those choices would be beneficial and more energy efficient. However, choices are being made that are wasteful of energy.

Underutilized options today
* carsharing
* bikes
* electric bikes
* public transportation – not very efficient without high ridership and utilization like in Asia
* lighter cars

Factors involved in selection are not just energy efficiency or cost of fuel. There is also convenience, status, practicality, overall trip times and many other complications in what people want and need or think they might want and need.

Benefits of light and narrow vehicles

The ability to use small, light vehicles means the ability to make transportation much more efficient. While electric cars are a good start (at least in places without coal-based electricity) the reality is today’s electric cars are still sedans and in fact are heavy due to their batteries. As such they use 250 to 350 watt-hours/mile. That’s good, but not great. At the national grid average, 300 wh/mile is around 3000 BTUs/mile or the equivalent of 37mpg. Good, and cleaner if from natural gas, but we can do a lot more.

Half-width vehicles have another benefit — they don’t take up much room on the road, or in parking/waiting. Two half-width vehicles that find one another on the road can pair up to take only one lane space. A road that’s heavy with half-width vehicles (as many are in the developing world) can handle a lot more traffic. Rich folks don’t tend to buy these vehicles, but they would accept one as a taxi if they are alone. Indeed, a half-width face-to-face vehicle should be very nice for 2 people.

Carpooling peaked at about 20% during the first oil crisis

Carpooling peaked in the US in 1970 with a commute mode share of 20.4%. By 2011 it was down to 9.7%. In large part this has been attributed to the dramatic fall in gas prices (45%) during the 1980s. In addition, the character of carpool travel has been shifting from the “Dagwood Bumstead” variety, in which each rider is picked up in sequence, to a “park and ride” variety, where all the travelers meet at a common location. Recently, however, the internet has facilitated growth for carpooling and the commute share mode has grown to 10.7% in 2005.

An Analysis of Vehicle Weight

A European project estimated the future scenarios for automobiles in terms of mass, fuel and CO2 emissions, analysing the maximum possible reduction of these characteristics.

First, an historical evolution of the mass, the engine power, the fuel consumption and corresponding CO2 emissions, the engine size, acceleration time from 0-100 km/h and finally the relation between power/mass was made on a sample of gasoline, diesel vehicles and an hybrid one. These vehicles were tracked since 1985 until 2008, when existed, and categorized according to the European Commission classification.

The maximum reduction of fuel consumption was studied, through the reduction of the weight of the vehicle, in its heaviest systems compounded by the body, chassis and powertrain, achieved by material substitution by lighter material as aluminium and carbon fibber, according to the fuel cycle model GREET.

The fuel consumption varies linearly with the vehicles mass. Simulating these vehicles, leaded to a maximum reduction of weight between 28% and 31%, of fuel consumption, between 7% and 15% and emissions of 98 gCO2/km until 160 gCO2/km, with the same percentage of reduction of fuel consumption.

Even in Europe cars have gotten 1.7 times heavier over the last 30-40 years.

A detailed analysis indicates that a 13% reduction in vehicle weight is expected by 2035.

The existing lightweight materials as aluminium, carbon fibbers, AHSS, HSS, titanium and magnesium are enough to cut off the weight of the automobile to save fuel. With a combination of component downsizing, redesign for example in terms of thickness, material substitution and a combination of these materials, a bigger reduction of weight can be achieved, consequently lower FC values and GHG emissions.

The maximum reduction of weight that can be achieved, by material substitution only, is between 28% and 35% using CF and Aluminium, as lightweight materials.

Very Lightweight Cars are possible and need to be made more popular and desirable

Edison2 won the 100 mpg Xprize. They have multiple initiatives underway, as the Very Light Car moves from a competition prototype towards a safe, comfortable, highly efficient car.

First and foremost, we have expanded our design team and are working on the next version VLC, a car that is roomier, friendlier and capable of meeting standards. Auto designer Jason Hill (formerly with Mercedes, Porsche and Aptera) has come aboard, as has industrial designer Peter Barnett (Northrop Grumman).

Also underway is an electric Very Light Car. Ron Cervan, formerly with Li-ion, joined Edison2 in 2011 and is spearheading this project. Although we chose an internal combustion engine for the X Prize, the platform efficiency of the VLC means a relatively small, light battery pack can result in a car with realistic range.

In this case, a 10.5 kWh battery, 114 mile range, and 350 MPGe.

Importantly, in 2011 we began a safety program with the Very Light Car. Both computerized crash simulations at Roush and our initial crash test confirm that with the right architecture a low mass vehicle can be a safe vehicle. A lot of work to do but we are on the right track.

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