I wrote:
The cars have to have a heavy-duty powerful ICE no matter what; they might as will use it at peak output from time to time to prolong battery power. High speeds and long-distance will both quickly drain the limited battery reserves of a plug-in hybrid, so you might as well resort to using the ICE early on.
This also reduces the weight of the add-on battery pack (the plug-in portion), which probably increases efficiency under some circumstances. There is probably a complex trade-off between battery pack size, the maximum speed cut off before engaging the ICE, the range you can travel with the plug-in battery pack, and so on. If you could fine tune the proportions for different drivers under different circumstances, you would achieve a higher maximum range, or a lower cost per mile, or less pollution (lower carbon emissions per passenger mile). For example, if you could pull out the ICE and substitute a lighter, less powerful model for one driver and not another, that might be optimum, but it is not practical. Toyota has to select a design that meets a broad range of user needs, which means compromises. The Prius is designed to be used in Japan, Southeast Asia and other countries with different driving patterns, speed limits, average commute distances and other factors compared to the U.S. It is a one-size-fits-all solution.
The biggest advantage the Prius has over other designs is that it exists. You can buy one. The Prius with the add-on battery pack is something of a kludge or compromise. It is a method of bringing a 1995 design up to the changed requirements and perceptions of the 2005 marketplace. Obviously, if you were starting over from scratch with another billion dollars of R&D money, and you were free to choose any battery you like without regard to patents or competition, you might settle on a different set of requirements.
The Prius+, with the add-on battery pack will give the average driver well over 100 mpg; probably 120 mpg, I guess. That is the "average" driver in the city, the suburbs, on a short commute or a reasonably long commute. In other words, if nearly everyone drives a car like this in 8 years, the US consumption of automobile gasoline will fall by a factor of five. (Overall consumption of petroleum would not fall that much, because long-distance trucks, railroads, aircraft and other machines would still use a lot of petroleum.) If everyone in the world drives one, OPEC will be bankrupt, and the main source of global warming will be reduced by a huge factor. That would be a fantastic outcome. We could start in for many it today, this moment, without waiting for another five or 10 year billion-dollar R&D project. (We could implement it now by buying regular hybrid vehicles and upgrading them with kits in a few years.)
Ludwik Kowalski's e-mail "sig" line is: "Let the perfect not be the enemy of the good." That applies perfectly to the situation. We should not wait for the ideal, perfectly up-to-date hybrid design to emerge. If I were in charge of the government, I would institute a crash program to apply this technology as is to all American-made vehicles starting to years from now. This crash program would resemble the decision made in 1940 to manufacture huge numbers of DC-3 aircraft for the war effort. The DC-3 came out in 1935. By 1940 it was somewhat obsolescent, because transport aircraft designs were evolving rapidly at that time, just as hybrid automobile designs are evolving today. After some debate, the government decided that to meet the emergency, they would "freeze" the design and make large numbers of a somewhat less-than-optimum machine. That was the right choice to make for a transport aircraft. It would have been a disastrous choice for a fighter or bomber. A transport aircraft did not have to go head-to-head in combat with German or Japanese models, so it would not be in competitive race to the death. Even though the Prius+ (upcoming plug-in model) is obsolescent, it has many advantages similar to the DC3: drivers have experience using it already (just as pilots knew how to fly the DC3 in 1940); it works well with the existing infrastructure of gasoline stations; it fits a wide variety of driving patterns; it can be developed for very little money; the design has been used extensively in the real world and the bugs have been shaken out of it. (The Prius is a second-generation design, with significant improvements starting in the 2004 model.)
By the end of World War II, the US did introduce larger four engine transports, and they were in widespread use by the time of the Berlin airlift. (However, DC3s were also used.) If we start manufacturing large numbers of Prius-style vehicles now, and Prius+ plug in models next year, in five or 10 years we can introduce a revamped updated design. It might even be designed by Americans instead of Japanese. Wouldn't that be amazing? Imagine Americans actually making their own advanced technology for once! (Okay, let's stop dreaming here . . .) There is no law that says we have to keep manufacturing these things for years and years, the way the Model T and the original Volkswagen beetle were manufactured.
- Jed
