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Mileage, Safety, Affordability: Pick Two
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I agree with the article. The fortwo is a good example. It's affordable and gets hybrid-like fuel economy (the only car on the market to get 40+ in EPA testing without a NiMH battery in the butt). Unfortunately, it's small and therefore not as safe as, say, a Chevy Malibu. It's the safest car of its size, true, I don't disagree, but to get the cost down and the gas mileage up, it's pretty small and therefore not as safe as something larger, more expensive and less fuel efficient. "Mileage, Safety, Affordability...pick two", is a good point.
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I think the first paragraph very accurately reflects the general attitude towards engineers that prevails among non-technically inclined people.
We live in a day and age where there are so many once-revolutionary paradigm shifting technological advances used in our daily grind that many people just take technology completely for granted, thinking that any challenge can be overcome by leaning on the engineers to put in some more overtime. Whats funny (in a dark sort of way) is when you encounter some non-tech type pushing some 'solution' that has an inherently insurmountable issue due to the most basic physics, to which they reply with disdain: 'just think outside the box!' Friggin brilliant.
But sadly these days it has become socially acceptable to be bad at even basic math. People have essentially 'grown up rich' (in terms of the wealth of technology we rely on every day), and thus think these things come easy. "I mean, we put a man on the moon, but we can't get a 5,000 lb, 350HP SUV to get 30MPG?"
Everyone would like cars to simultaniously get safer, cheaper, and more economical, so this is easy (albeit irresponsible) politicing.
We live in a day and age where there are so many once-revolutionary paradigm shifting technological advances used in our daily grind that many people just take technology completely for granted, thinking that any challenge can be overcome by leaning on the engineers to put in some more overtime. Whats funny (in a dark sort of way) is when you encounter some non-tech type pushing some 'solution' that has an inherently insurmountable issue due to the most basic physics, to which they reply with disdain: 'just think outside the box!' Friggin brilliant.
But sadly these days it has become socially acceptable to be bad at even basic math. People have essentially 'grown up rich' (in terms of the wealth of technology we rely on every day), and thus think these things come easy. "I mean, we put a man on the moon, but we can't get a 5,000 lb, 350HP SUV to get 30MPG?"
Everyone would like cars to simultaniously get safer, cheaper, and more economical, so this is easy (albeit irresponsible) politicing.
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Amen.
2015 Cadillac XTS Platinum, 2014 Cadillac Saks 5th Ave ELR, 1989 Merkur XR4Ti, 1989 Merkur Scorpio
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I saw a fortwo the other day... the thing makes my Miata look huge.
It'd be a speed bump for my Tahoe. Buy one if you have a death wish...
We spent 0.8 percent of the U.S. Gross Domestic Product annually on the race to the moon. The U.S. GDP today is about $13 trillion... 0.8 percent of that would be one hell of a committment.
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Oh I will! I will! Bet ya say that to all the people out there that ride motorcycles, or walk, or heck even get out of bed in the morning! Don't worry, I'll watch out for SUV's since they tend to not watch out for anyone. At all. I bet a smart is safer than your Miata, but I wouldn't want to meet your Tahoe, in either one, although with the fortwo, at least your head won't be the side impact beam like it would in the Miata. Your eyes are at SUV bumper height in the Mazda, in the smart you can see over the hood. Make your choices, take your chances, no matter what you drive.
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Californians make me very angry. Very angry indeed.
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And what are Californians doing to you? Remember, it isn't all Californians, it's the elected officials.
OK I am putting all the politics and BS aside and asking a technical questions to all the engineer and mechanical types out there. Shouldn't horse power be in the mix? I thought I read somewhere that if you tune an engine down X% in HP you could get a Y% gain in MPG. If this is true does every car need 250+ HP? Do we all need to go 0-60 in 5.0 sec? Can't a car be safe, affordable and get better MPG if it is slower than all they are now? The average car has much more HP now than most did back in the day. Are we spending our tech advancements to get more power instead of more MPG?
Just give me technically correct answer. Not "I have the right to blah blah, or "people will always want more blah blah" . Just form an engineering point of view can lower HP give you better MPG for a given engine?
Just give me technically correct answer. Not "I have the right to blah blah, or "people will always want more blah blah" . Just form an engineering point of view can lower HP give you better MPG for a given engine?
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And those elected officials know the answer to everything....just ask them. One thing they have been very successful in doing is making sure the public blames the auto companies for poor fuel economy. It's certainly not the federally mandated vehicle safety standards (air bags, stability control, structural standards that all add weight and negatively affect fuel consumption) of course. And it can't be that customers demanding ever larger and more powerful vehicles are to blame. No, of course not. While I too am disappointed in the fuel economy of many vehicles these days, I understand the predicament the auto companies are in; satisfy customer demands for functionality, size and power, satisfy the government's safety standards and try do it all with maximum fuel efficiency. It's no easy task and it's foolish and naive for the public and the government to assume it is.
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I am no engineer just an aircraft mechanic, but I have been studying this type of information in my spare time. I eventually would like to build my own car from scratch and a series hybrid at that, just for fun; if I ever had the money of course.
The answer to your question is difficult. There are more aspects to fuel efficiency than engine size and power. Basically, it works out to a common equation. It takes X amount of power to get Y amount of resistance(drag, weight, etc) to Z amount of speed in a certain amount of time. But, the slower the acceleration doesn't necessarily save you gas. And at the same token it takes X amount of power to maintain Z amount of speed with Y amount of resistance.
So, basically you will need so much power no matter what you want. And, in order to get said needed power you will need to burn so much gasoline. Each gallon of gas has about 124,000 BTU's of energy. It takes so many of those BTU's to convert into mechanical energy to create the amount of power you need to get up to speed and maintain it. An engines potential power does not determine it's fuel efficiency, how you use the engines power does.
Now, on with the weight and drag issue's. These are reasons for the efficiency problems that even the small trucks have. The are like brick's in the air and they weigh a lot. A truck or SUV needs to push through the wind while cars can sort of slice their way through it. Weight has become an issue for all cars and trucks today. There are many regulations that require extra materials to strengthen the cabin of a vehicle which adds more weight which means the rest of the vehicle has to be beefed up to handle 200,000 miles of abuse with all this weight to lug around which adds more weight(vicious circle really, and it gets worse), then people want their 8 way power seats and triple zone a/c with the four 25 lb speakers and 75lb wheels (I am guilty of this, but I can afford the gas). This is the other part of the equation. The more weight you add the worse the mileage. Then you throw in the aerodynamics of a parachute. Well, you get the picture.
Now we have to look at the efficiency of an internal combustion engine (ICE). They are only about 30% efficient and these are the best ICE made today. This means that a 250hp engine is actually putting out more than 750 hp, but we are only able to extract 250hp into mechanical power. The rest is lost through heat, pumping losses, and friction. We also have to look at the advantages for every type and size of engine. Some engines work better than others in low rpms like big V-8's and diesels, while others are better at revving high like smaller 6's and I-4's. V-8's and V-6's have an advantage over I-4's in bigger cars and SUV/Trucks. The V-8 or V-6 can almost idle a large vehicle at highway speeds giving the engine less heat and friction to overcome, while a I-4 would be high revving. But, I-4's are great around town because they don't use much gas to get you to speed because they use less gas to rev up. This can be compared easily with a Mazda CX-7 and Saturn Vue. The Mazda is a Turbo 4 while the Vue is a 3.6L V-6. The Mazda gets 1mpg better in the city while the Vue gets 1 mpg better on the highway. On the other spectrum an I-4 is better than a big V-8 in a smaller car because the car doesn't require as much torque to maintain speed.
I guess it's all about balance. But, asking for more than a material can physically deliver is an impossible request. That is where alternative energy sources com into play. Hybrid electric cars and such, but they are still being powered by the same inefficient ICE. The only things a hybrid does is take the wasted energy (braking and coasting etc.) and store it to supplement the inefficient ICE at certain moments. It also, and more importantly, turns off the engine when it is not needed; no gas burned equals the best mileage you will ever get. This does work, but it is still only so much of an improvement and doesn't fix the inefficiency issue of the ICE.
In order for an ICE engine to become more fuel efficient new technology that has never been thought of before will have to arise. Hence the comments about engineers and scientists having to work overtime because the ignorant public demands something. Something that they them selves cannot deliver or even contemplate on considering to possibly think about studying to understand a solution that could maybe one day lead to the eventual replacement of the fossil fuels they so direly want to be rid of.
So, in short, to answer your question. Yes and no. A 430hp Corvette will beat out a 170hp Solstice in fuel efficiency when cruising, but put these guys on a track and the Solstice won't have to fill up on his way home; even if he lost the race. The application of the power delivered by certain engines in certain vehicles will determine the mileage of said vehicle.
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Well, seeing as how they're elected officials that represent the people and their methodology for trying to force technology is hardly a new development, we can only surmise that their views are representative of their electorate.
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Most Californians I know are stuck up like the people from Texas and to a lesser extent Hawaii. They all think it is the best place in the world and nothing can even think about possibly competing with their state. But, California accels at making it hard for any domestic product to be sold there. 43 mpg by 2016? Are they nuts? The only thing that will be able to sell there will be Mopeds, Motorcycles and a Prius. GM better hurry up with that Volt if they want to be a competitor in that market other wise Gov. Swarts will effectively give California to Japan. Not it's not all the people, I have many friends in Cali, but the government is a direct reflection of the majority of the people. And, for this issue with California always pushing too hard with emissions laws going on so long. We no longer blame just their government, we start blaming the people that kept the government in place. How many Californians do you think will be pissed in 2016 when the only car they can buy is a Prius and they own a 19' boat?
I guess the moral of the story here is be careful of what you wish for. You might just get it.
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The answer is yes.
In a very simple nutshell:
Holding everything else constant, the more air an engine can pump the more fuel can be effectively used to generate power.
Want to use less fuel? Pump less air. There are ways to do this without going to a smaller engine, and you will use proportionally less fuel.
Perhaps with the trends with fuel prices as of late, hopefully automakers will see a significant market for lower powered high MPG versions of the cars that have 250HP cars, a market that hasn't really existed until very recently in this country.
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The answer is also no. You can have an engine rated at 400+hp, but pumping less air doesn't equate to less fuel used. The reason for this is that you are going to NEED a certain amount of fuel no matter what the engine size or power rating is in order to get up to and maintain a certain speed in certain car; every single time no matter what. Put a 170hp I-4 in a Corvette and you will probably get no improvement in mileage. Compare a Solstice to a Vette and you will understand my point. Put an I-4 in a Suburban and will probably loose mileage; even if the I-4 is rated at 300hp. It still has to rev higher to maintain speed. Hell, compare an Aveo to a Cobalt. The Aveo is lighter, smaller, and has a less powerful smaller engine and yet it only manages a very very narrow advantage on the hwy and no noticeable difference on average.
Like I said in a previous post. It's about balance. The solution to the problem isn't making less powerful engines because it won't make a difference. The solution is to find a new technology or engine that is much more efficient than an ICE. Or replace fossil fuels all together. That is exactly why GM has been building Flex Fuel vehicles for years now and why GM is pushing the E-Flex system and Hydrogen. E-Flex will allow GM to adapt to any changes in the refueling/energy industry without compromising performance. And hydrogen is plentiful. Imagine buying a Volt that runs off of bio-diesel or hydrogen. Or converting it to run on natural gas or another source of similar style gaseous fuels. No matter what the change in fuel is, the Volt will still drive the same way. Power and performance will be the same and fuel efficiency, although it will change, will stay basically the same; very high.
We need to raise efficiency and lowering power will not make an ICE more efficient. It will only change how fast people can accelerate and the top speed of the vehicle; something simple driving habits can fix.
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I think the key there for most people is the 350hp and 30 mpg. The problem is that the weight of vehicles is so absurdly high that there can be no hope of achieving a decent fuel economy rating. People don't really care what the vehicle weighs because it's not on the sticker and it doesn't mean anything by itself. Instead they care about perfomance, both outright and in terms of fuel economy and safety.
I'm guessing you're an engineer, so maybe you could answer this. If you kept the aerodynamics of a Chevy Tahoe constant and the same technology under the hood, what would happen to fuel economy if you lowered the weight by 1000 lbs? What about 2000 lbs? Instead of a 5000 lb SUV, it would be a 3000 lb SUV. Currently, it gets 20mpg on the highway with no hybrid, just the cylinder shutdown technology on the V8. How much would lowering the weight by 20% or 40% increase both mpg and acceleration/braking/handling etc?
Yes, lighter materials are currently extremely expensive, but they also aren't manufactured on any kind of scale. Costs can come down when processes are refined and scale is increased. Maybe our engineering resources should be directed away from the driveline and onto the problem of weight reduction and manufacturing lightweight materials.
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