Don't worry, Totally_Lost, no one will take away your SUV that you need to get to your mountain house. There is a right tool for every job, and SUVs are generally not the tool for commuting. You have a point when you say that maybe some cars shouldn't be allowed on the highway, and at the same time, maybe large cars should not be allowed in cities. You are completely wrong saying that do-gooders killed thousands of people. On the contrary, do-gooders have save countless lives from people like you who fail to realize the importance of government regulations and intervention. People kill people, cars kill no one. Your point about driving a bigger car for safety will just encourage larger and larger cars. With your mentality, only people with enough money for the largest cars will be safe.
Again I must corrct you, Totally_Lost. In your first post you refer to "tree huggers", and a couple of posts later you called someone's opinion "stupid", at the same time you were inferring you had done a Doctoral thesis on something. "do the PhD thesis..." then you claim the "do-gooders" are out to get you. It just seems like you point is to help the "do-badders". You make some good points, but your written rhetoric incites people, so don't be suprised when you get opposition.
It turns out you have a B.S. in computer science. How does that qualify you as an expert on drive-trains and physics? Your resume shows no design experience as you would elude to in this forum. Did I miss something or do I have the wrong guy? Your business looks like a computer systems consulting firm, you also do automotive and EV design?
The problem with the regulations is not can you safely build "a car" that can get 54.5pmg, it is that you must build a fleet of heavy and light cars with an average of 54.5mph. That average problem, pushes some cars to perform well past 54.5mpg, that are excessively light and unsafe. This is what happened in previous CAFE cycles.
The "Smart Car", and other micro cars, while they met minimum cabin integrity crash tests, are also significantly more likely to injure or kill occupants in a crash because of substantially higher G forces and rotations in a crash. Some try to play down the IIHS safety testing, because the testing isn't representive of typical non-injury crashes .... there is however a better corrilation to the types of crashes that do injure or kill. And because of that, the IIHS crash data is very important, not only for insurance companies to set actuary tables, but for consumers to judge injury/death risks that are higher in smaller cars.
It's the many micro cars that will be built to meet fleet averages, that I believe are morally wrong. These cars will again be discounted in price/margin to encourage additional sales to meet fleet average objectives. This forces young and poor people, with cash strapped budgets, to drive cars that are unsafe at highway speeds.
Several posters have praised the goverment for all the "do gooder" safety improvements in cars. Well as far as I'm concerned doing a few good deeds, DOES NOT make up for killing thousands with regulations that will force unsuspecting drivers to buy unsafe cars in crashes above 45mph.
If the regulations had created a model for low speed city only cars with a maximum speed of 45mph, and heavier cars for highway and city use that can safely travel at 75mph, then we might be making progress.
It's the physics of this problem that makes engineering tradeoff's impossible. The kinetic energy is proportional to the square of the velocity. 45mph squared is 2025, and 75 squared is 5625, about 2.8 times more energy that must be absorbed by the frame and cabin in a crash. That means in general that the car MUST use about 3 times heavier metal AND be larger for longer crumply zones to be safe at 75mph. This wieght difference means that both smaller cars, and larger cars, will tend to be built lighter than is safe. In the last CAFE cycles we saw full sized 5 passenger sedans, down scale in size, and safety ... along with the introduction of disposable small cars that killed thousands.
The "do gooders" didn't do us ANY good in that ... and killed thousands .... including lots of kids in young families with a tight budget.
Circling back to "54.5 MPG Comes With Trade-Offs," having cars that already achieve and exceed this CAFE number, this is not that hard of a problem. We have examples and for the price of royaltes, any car manufacturer can reach this target. It won't be free (but my fees are reasonable <grins>) but it will be interesting. Certainly, there are more than one way to achieve this level of performance.
Fossile fuels are a finite resource. Although we've started making renewable fuels, they need to be used as efficiently as possible. Compared to going to the moon, it isn't that hard of a problem and unlike the moon effort, needs to be replicated year-after-year, day-after-day. It can and should be done if we have the wit and will to do it. The technology is available even today.
About the tone of our postings, I prefer to let the data, reproducable metrics, show me the way and try to not let personalities or style get in the way. One of the most brilliant engineers I ever met, Steve D., also had Yankee speaking patterns so he would treat my in-breaths as a break in my speaking and jump in with his thoughts. Often brilliant thoughts, it was rude to my Southern way of speaking. Yet inspite of his conversational quirks, we would often interate to common engineering solutions.
What I found was more important than style, certificates, diplomas or awards, the most important thing was in the data, the results. Especially those that are reproducible, not ancedotal, one-of events. So I take time to carefully measure what is going on and elminiate or minimize variables such as altitude and wind effects. I can't control every variable so I repeat the tests on other days to minimize their effects (aka., weather.)
There are high mileage folks who live on ancedotal stories . . . 'I got <whatever> once.' As nice as these records are, one-time observations need to be especially well documented for environmental variables and route including altitude changes. Then and only then can we begin to make an accurate model that others can replicate.
You wrote,". . . pickup a fuel flow sensor, and a GPS to track course, speed, and rate of climb so you have detailed real-time mpg data . . ." Already done using a data recording OBD scanner and GPS mouse.
AutoEnginuity makes an OBD scanner that operates on any general purpose, Windows laptop and can record data metrics with ~100 ms sample rate. A GPS mouse will report three axis emphemeris to the same laptop. These can easily be combined into comma separated values (CSV) for excel analysis.
I used this technique on a 750 mile drive to Washington DC, 120 mile drive to Nashville TN and several, shorter routes around town and the county. There are some transient events where the sampling rate can not follow things like maximum acceleration and braking but these are easily identified and trimmed out. But insights gained improved my driving rules for mountain/hill driving.
For example, fuel injected engines must have an accurate mass air flow to maintain a 14.7-to-1 mixture. This one metric gives a very accurate fuel flow at the OBD sampling rate. Unique to the Prius, MG1 torque has a fixed ratio to the engine torque so combined with engine RPM and fuel flow, we have generated a functional, BSFC chart based upon the engine in use . . . the operating line.
You asked,". . . The Grey "mpg fixed" line, looks pretty close to what should be a typical efficency curve from zero to reasonable speeds. The dark blue "mpg w/o fixed" I'm still trying to figure out what it might be."
The "gray" line is the total energy loss as a function of rolling, aerodyanmic, and measured electrical overhead loss. The Prius has a measured, electrical overhead of ~450W. I've not tried to break the 450W down to specific subsystems but this includes daylight running lights, control computers, cooling pump(s) and power brake pump. There is another, unquantified heat loss from the engine that tries to maintain a temperature between 60-90C.
The "dark blue" line is just rolling and aerodynamic drag energy loss expressed as MPG. If there were no overhead losses and the engine had a fixed efficiency, this would be the peak, expected MPG.
These are drag and overhead driven curves that assume a constant engine efficiency. However, engine efficiency is not linear across all power modes and is complicated by the ON/OFF engine cycling and CHARGE/DISCHARGE efficiency of the traction battery. The real world is often non-linear so I augment these curves with specific data points from various sources and my own benchmarks.
There are optimum and suboptimal speed ranges that are model dependent so we're always looking for 'the knee in the curve.' For example, 65 mph in the 2001-03 Prius marked the knee in highway speed: 52 MPG @65, 49 MPG @70, and 39 MPG @75. But what remained of this knee moved to 85 mph in the 2004-09 Prius. We don't have enough data for the 2010-current models to document a knee.
Thank you for toning down your insults ... I politely warned that I can play that game too, well before carefully choosing how to join your game, since you thought it was so fun. BTW, what you think may be common sense, is really more like your lacking the experience and training to understand more difficult parts of the design problem. Believe me, there are a lot of good engineers that completely miss how to deal with these problems ... not because they are stupid or ignorant, but simply because this stuff isn't easy, or intuitive, and they lack the personal experience of designing in this field.
Actually, the nice part about these forums, is that there is a written record for people to review the facts about what was written. In my first several posts, there isn't any name calling despite the analyst and your self doing the "you are totally lost" insults. So, it's not nice to lie about your disrespectful actions in this forum, the record is clearly here to read. I did get tired of you purposeful insults, and thought it was time you started getting some of it back .... I'm glad it worked.
I also happen to believe that hybrids in many forms are the correct thing to do, it's just that serial hybrids using electric traction motor to move the vehicle from stop to an optimum speed is significantly less efficent than other choices. Again, if you read back, I clearly said serial hybrid is bad for startup, and parallel hybrid with a good transmission (CVT) is significantly more efficent if you use the same ICE and controls, as it completely removes the generator, and traction motor losses from startup and normal drive operation. A parallel hybrid allows for a significantly smaller ICE, as the electric traction motor can assist during high energy demand periods, while both the ICE and the electric traction motor are operating near peak efficency. It also allows for a smaller traction motor for assist, which improves efficencies by removing copper heating losses and cooling for the traction motor that is required with sustained operation, and less of a problem for intermittant assist.
Both the RFL and goverment papers address iron core eddy current losses, which are very difficult to design out of this class of traction motor without carefully understanding the pure physics issues well. RFL did about the best job I've seen to date for that class of motor. I prefer air core designs, but they are much more difficult to get up to 60KW because of cooling issues. For a smaller light HPV/EV that I'm working with it's not a problem, and allows building motors and drives with the exceptionally high CISRO efficencies. As long as you are designing for city street speeds, there are a number of very good tradeoffs to lower wieght, lower drag, and lower operational losses that are inherient in designing systems that must also do 75mph on the highway.
What I do not like about CAFE regulations, is that the smaller lighter cars are not safe at speeds above 45mph, and that is the likely design tradeoff that will result from mandating 54.5mpg.
That I believe is wrong, and will kill a LOT of people, and a LOT of kids.
A better approach is to introduce lighter highly fuel efficent hybrids for low speed city use only, and HPV's, with market driven incentives ... not government mandates that will kill people and kids.
Currently government regulations require separate registration and insurance for every vehicle, not every driver, so that it is VERY expensive to have a smaller fuel efficent car for local city driving, and a larger heavier car/truck/SUV in a family for times when you really do need to haul a load for your work/business, the soccer team, band, or other large group of kids. I personally was the "bus" for all my kids events with a 9 passenger Suburban ... which is a lot safe to haul 8 kids for sports, band, robotics, and other school events than letting kids ride stuffed in a smaller unsafe car with a distracted driver.
My kids are in college now, but I still frequently need the truck/suburban for my businesses. I volunteer at the local high school as a coach/mentor for the robotics team, and still haul them around the state for competitions during the winter. I've done a lot of over the road driving, some 2.5 million miles, a lot of that in very bad winter weather. I've also logged a lot of off the road racing in dune buggies and other off road toys to have the experience playing control games when things are going wrong ... I know that the kids are safer in the suburban if we are hit by an out of control newbie driver on ice/snow.
Removing safe 8-9 passenger SUV's from the population is bad ... it will kill a lot of kids, or force less environmentally sound choices like transporting a dozen kids on a 60 passenger school bus.
Things to fix, are changing registration and insurance rules to insure the drivers as a family pool, and remove the requirement to buy the largest vehicle that you only need sometimes. Road's are paid for with fuel taxes ... the whole EV and Hybrid market is breaking the very system that fairly distributes the cost of road maintence, by miles driving on those roads. A better choice is to remove taxes for road maintence from the pump, and place it on the vehicles by weight and miles travelled per year. That includes Bicycles and other HPV's, so that road construction and maintence funds are available for bike lanes on all streets, and where traffic is heavy, using those funds to build separate bike paths that are away from the street.
I am sorry you are insulted by common sense, though I am not suprised. Such a response of name calling is a sure sign of a weak case, certainly is not an intelligent response. You seem smarter than that, but you were insulting and used name calling in your initial posts. You can whine all you want, but it doesn't make your point any more valid. I do commend you efforts, if indeed that is true, towards wind power and EV technology, if what you say is really true, then this standard of 54.5 mpg should be easily attained, they just need to talk to you about how to fix their inefficiencies. I don't know why you would oppose such a standard. I also applaud any effort from anyone who puts their money on the line for progress. I do not think that name calling is a very productive way to get your point across. People will disagree, but part of the learning and communication process is listening. You seem to have a real problem with hybrid technology, but it is here to stay: http://www.autoblog.com/2007/07/16/hybrid-toyota-supra-wins-tokachi-24-hrs/
BTW ... I started hiring engineers last year to design a product similar in scope/function as this, that should reach market next year ... project is still stealth, but I did register the domain as nutrike.com:
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