Which Path for Auto Power?

I was looking at a new Chevy Z-71 truck last year. The sales brochure stated it was the flex fuel type. It was also stated that it had the same horse power rating when running on either gasoline or ethanol. I have been told that the ethanol has a lower BTU output and therefore requires more ethanol by volume than gasoline. So, in order for ethanol to be comparable in value to gasoline then it should sell for around $0.50 per gallon cheaper. I am not mentioning this to muddy up the waters for researchers and there endeavors for alternate fuel sources. I am posting this asking for clarification.

Just to clarify. During combustion, you consume twice as much ethanol,methanol as gasoline for the same amount of energy produced. The nice thing about ethanol is that it is a RENEWABLE resource unlike fossil fuels. But be under no illusion here, the gasoline companies still have the distribution network to distribute whatever fuel we use in the future. Do you think they will charge us any less than they are charging us for gas now??????

UFG

No doubt in my mind that we will be charged as much as possible. We've seen that already. Just the threat of a hurricane sends fuel prices up. But, even with no damage the price stays high for several days before lowering. Then it usually does not go to the pre-storm price. I will admit that early on I was for grain for fuel. Now with food prices going out of control because feed stock is being made into fuel I am not so sure. I have not taken time to see if this is smoke and mirrors. I do find it hard to believe that we could have a grain shortage because of fuel production. I was raised on a farm. I realize that there is only so much grain to be squeezed out of an acre. But there are a lot of acres being farmed and many more that could be. Maybe I am just having a hard time comprehending the true scale of the market.

This issue gets profoundly complicated, because there are so many artificial (non-market) forces at work. The price of E85 is subsidized, because an influential group of lobbyists think it should be subsidized to encourage people to buy it, to counter the fact that you need to burn far more of it to create the same hp. (Because of this, a 15 mpg Chevy Tahoe gets 11 mpg on e85, per a Car and Diver test... I think those figures are right... it might have been 16 on gas). Grain production is also subsidized for other reasons, so farmers are paid not to produce it.

If there were only market forces then the amount of grain on the market would match demand pretty closely, because farmers would not want to throw away part of the crop each year. In that case, suddenly using a lot of grain for ethanol (as we have done) would drive up prices for food (as has happened).

Were it not for the subsidy, no one would buy ethanol -- why would you want to?

Manufacturers have a different reason for building flex fuel vehicles (and promoting them as if they are "green"). There is a 6.67:1 advantage given to alternative fuels in the CAFE standards. Because flex fuel vehicles are considered to run on gas half the time and ethanol half the time (for the purposes of calculations) the factor applied to a flex fuel vehicle is 3.33. So a 15 mpg gas guzzler, which would otherwise be subject to about $250 in CAFE fines (per vehicle produced) is rated 50 mpg, which allows GM, (for example) to build loads of other gas guzzlers while keeping it CAFE results out of fine territory. The flex fuel hardware ads $30 to vehicle cost, so its a good deal for the manufacturer. They get to sell a vehicle that gets 11 mpg on ethanol, but it is treated as if it is as efficient as a Prius.

Re getting jerked around by gas prices: The prices in the Atlanta area were as high as 9.99 per gallon recently. $5.00 was fairly common. For a lot of people, these prices (and the lack of access, with two-hour-long lines) were a major hardship. Meanwhile, Exxon posted record profits. (Now, prices in Atlanta are around 2.20 or so.)

Does this kind of thing breed cynicism?

Ken,

By what rationale does CAFE give a 6.67 advantage for flex fuel?

Hi Seaplaneguy:

It's a political incentive for alternative fuels. The number seems far too high to me.

Any alternative fuel is considered 6.67 times as "good" as gasoline or diesel fuel. There isn't any logical (technical) reason for the number, and using it produces some ridiculously high "MPGe" figures for both flex fuel vehicles and electric vehicles.

For electric vehicles, you first calculate the well-to-wheels efficiency, which produces for a GM EV1, 64 MPGe. If your vehicle runs on electricity alone, as the GM EV1 did, then you get the full 6.67 multiplier, making the rated mileage around 400 mpg. That allows you to produce a lot of gas guzzlers without incurring CAFE fines.

Most ethanol produced today consumes substantially more energy than producing gasoline does, so the whole thing seems like a bad deal.

Hi Fry,

Thanks for the reply.

Might you have some references to this multiplier so that I can wrap my little brain around this "smart" idea?

Thanks,

Seaplaneguy

Here's the section of law

It says

"The PEF is based on the existing regulatory approach at 49 U.S.C.32905 for determining the petroleum-equivalent fuel economy of alternative fueled vehicles. The calculation procedure converts the measured electrical energy consumption of an electric vehicle into a raw gasoline-equivalent fuel economy value, and then divides this value by 0.15 to arrive at a final petroleum-equivalent fuel economy value which may then be included in the calculation of the manufacturer's corporate average fuel economy."

If you scan down from where that quote is located, you can see that they start out OK, and calculate a reasonable well-to-wheels equivalent. But then they divide by .15 (multiply by 6.67) for no apparent reason.

If you read through the whole thing, you can see various comments made, but the gist of it is that there is no real reason for the 6.67 multiplier -- it's just there to favor alternative fuels and electricity.

SO...

"Thus, DOE stands by its proposal to provide electric vehicles the same reported-fuel-efficiency incentive (the 1/0.15 factor) that other alternative fuel vehicles currently enjoy."

So whether the alternative is electricity, ethanol, dog dirt, weasel urine, snake oil... it's all the same to the DOE. As long as it is "alternative" it is 6.67 times as good as gasoline.

At the end they give an example. The 244.75 watt hours per mile average would be about right for an efficient small electric car. The Tesla, not all that efficient, is about 300 watt hours per mile. A normal well-to-wheels approach would call that 50 MPGe. That's about right both in terms of actual energy consumed (i.e., the mix of coal, natural gas, etc), and also intuitively: It happens that the Prius engine is 37% efficient, which is about the same as powerplant efficiency, and gasoline is produced with 80% efficiency, which is fairly close to plug-through-motor efficiency... so it makes sense that an efficient electric car and a Prius would have about the same overall efficiency -- they both use the same amount of resources per mile (coal,etc in one case, petroleum in the other).

But 50 MPGe doesn't sound good enough, so they call it 335.24, which lets GM produce loads of gas guzzlers for each electric car they turn out.

It's pretty classic: create a law to give the appearance that politicians are doing something about fuel efficiency. Then create huge loopholes.

Ken,

My calculation is: 1/(.244 kw-h/m x 3412 btu/kw-h x gallon/125,000 btu) =150 mpg

300 watt-hr/mile is 122 mpg. Same page?

To get 50 mpg, as you state, I don't follow that...

.37 x 150 = 55.5 mpg

.37 x 122 = 45.14 mpg

I can see .15 if they consider a gasoline engine to be on average 15% efficient, which is not that far off "on average". I don't think a Pruis is 37%, but more like 25% because it is limited by the engine itself, assuming no plug in. The grid is about 33% from what I have read, "on average."

If a Telsa car is only getting 122 mpge, that would be 18.3 mpg in a gas engine version if you use .15 factor. I would guess such a car would get 30-35 mpg with a gas engine, much like the Lotus two seater does (so I hear), no? A Corvette gets only 12 mpg on average city and it is low in drag. An electric corvette would likely get about 122 mpg too.

The problem with all this figuring is that it actually hides the real efficiency of the engine power system within the aero and rolling drag. If a person needs a large vehicle vs a small commute car, mileage standards don't take that into account, and just force out larger cars.

So, could you help me on your numbers...

Thanks,

Seaplaneguy

Hi Seaplane,

The well-to-wheels approach has been used to compare gasoline and electric vehicles in terms of how much fuel energy each uses, and the relative environmental and resource depletion costs of that fuel. It can be somewhat contentious, because there is such a wide range of fuels used to produce electricity (as well as methods that use no fuel in the conventional sense). The approach is also used to assess whether or not it makes sense to produce and use things like ethanol, etc, but again it can be contentious, with some forms of ethanol being (according to some studies) far worse than using gasoline, because you use as much energy (in petroleum alone) in producing the ethanol as you get out of it as a fuel (tilling fields, making fertilizer, harvesting, trucking, heating the fermentation vats, etc.).

Your 33% efficiency for generating electricity is a pretty good figure, and that is what is used in the CAFE standard. (The GREET figures use 38%, and may be more accurate, being newer.) Producing gasoline is quite efficient, at 83% (CAFE) or 81% (GREET). The CAFE calculation* uses these efficiencies to come up with a "gasoline-equivalent energy content of electricity" – in other words, the actual kilowatt value (33.7kWh, based on 115,000 BTU per gallon) of gasoline, adjusted for the low efficiency of generating electricity. The CAFE figure is 12.3 kWh per gallon. So you can say that if an electric car consumes 12.3kWh of electricity, that is equivalent (in resource usage... and, roughly, in CO2 production) to a gasoline car consuming one gallon of gas. If both vehicles go the same distance under the same condition, then the two vehicles are equally efficient at using our resources, from well-to-wheels.

This sort of analysis is the answer to electric car nuts who think that their vehicles are zero pollution, and gasoline vehicles are evil incarnate. The approach enables you to compare, for example, the first Honda Insight which could get 60 mpg with the GM EV1, which used 190 Wh per mile. Both are about the same size, both are highly optimized, both quite well streamlined. 190 Wh per mile is (12,300/190) 65 MPGe. So you can say the EV1 is highly efficient, but not much more efficient than the Honda. For each 100,000 BTU of petroleum in the ground that the Honda uses, 17,000 BTU is lost before it gets into the Honda tank, and then 70% of the remaining 83,000 (.7* 83,000 = 58,100) is wasted in combustion, leaving 24,900 BTU at the flywheel.

For the EV1, 100,000 of grid mix fuel is burned at the powerplant at 33% efficency, and after line losses, 30,307 arrives at the plug. If charging, controlling, and the motor itself were 24900/30307 % (82%) efficient, then the two cars would be identically efficient, WTW. That 82% figure is pretty close to right, so my 30% engine efficiency guess above for the Insight is too high, but close enough to illustrate that the two vehicles are very close in their use of resources. Electric vehicle nuts who think that their vehicles are incredibly green, are... nuts. I happen to be an electric vehicle enthusiast, but realize that today, running on the grid mix, they are not the panacea that the true nuts would have you believe. Eventually, as they are powered by wind, solar, etc. they will be very "green" (and even that makes the assumption that solar cells will continue to be produced more efficiently: the fact that they now cost an amount equal to 10 or more years electrical output in many places suggests that a lot of energy goes into their manufacture.)

So far, all this is stuff engineers can agree upon. The .15 factor, on the other hand, is purely political. It is applied after you've done the math to compare actual resource use. For a while it was called a "scarcity factor", but in the CAFE law it is called the "fuel content" factor. The fact that the same factor is applied to any alternative fuel is basically... nuts. But at least so far, it is not a huge deal, because it only applies to CAFE, and enables manufacturers to get away with selling more gas guzzlers, in proportion to the number and efficiency of "alternate fuel" vehicles they sell. Only GM puts out more or less large numbers of flex fuel vehicles for this purpose, and you could say they are abusing the system, knowing that 1. hardly anyone actually fills up with E85, 2. even if you want to fill up with E 85, you have a hard time because there are so few stations that have it, and 3. there is little compelling evidence that ethanol is "better" as a fuel, anyway. But GM would argue: "Hey, the law is there to take advantage of."

You can see why GM has been pushing to have their upcoming Volt considered an electric vehicle, instead of a hybrid (even though is clearly a plug-in hybrid, that perfectly fits the SAE definition). As a hybrid, it would have a sticker rating of 48 mpg, but as an electric, it would have triple that – because so far, the plan for sticker purposes is to use a plug-to-wheel rating, not a WTW rating. PTW, the Volt would be rated 150 mpg or so. But given that this figure does not account for the gasoline used when the Volt goes beyond its 40 mile range, it seems pretty deceptive. Also, it suggests that the Volt is three times as "good" environmentally as the Prius, but, for the same reasons as mentioned above re the Insight and the EV1, the two are very close to equal. (Once beyond the 40 mile range, and cruising on the highway, I'd be surprised if the Volt can match a Prius, let alone beat it – the aero is not as good.)

There are loads of promoters of plug-in Prius conversions. Adding more batteries doesn't improve the basic efficiency of the car, it just allows you to run less on gas and more on coal. (The excess weight actually reduces efficiency a little.) But even so, the promoters of these conversions have claimed 150 mpg, 300 mpg, and even 500 mpg... all based on ignoring the electricity used. As you can probably guess, you can make up any figure you want, by adjusting the "typical" trip length... and it doesn't even matter what size the battery pack is. Some of these conversions only go 10 miles on batteries, so they say: "If you drive 11 miles per day, in a week, you will have driven 77 miles but will have only used the gasoline to go 7 miles. 7 miles at 45 mpg is 0.15 gallon. 0.15 gallon for 77 miles is 513 mpg." The figure suggests extreme efficiency, but the actual efficiency is no different that an ordinary Prius.

The dollar cost of energy is another issue, entirely. Today, in most places, electric cars are much cheaper to operate, if you ignore battery replacement costs. Even with battery replacement costs taken into account, they remain cheaper, especially if you compare engine rebuild costs. (This applies to well-designed conversions, not to cars like a Tesla or a Fisker, which are so expensive that economy of operation is not a rational concern.)

Re: Prius engine efficiency. The Prius engine actually spends a lot of time near its peak 37% efficiency. Somewhere, I have the BFSC map for the engine, and fairly large areas of the map are in that range, and the operating routine keeps the engine in that range much more of the time than if the engine spent more time under light load, as it would in a traditional car. (Although even then, with the other tweaks the Prius has for efficiency, the Prius would still be very efficient – although it would also be a dog, because during acceleration you'd only have an undersized engine to rely upon.)

* Eg = gasoline-equivalent energy content of electricity =
(Tg * Tt * C) Tp
where:
Tg = U.S. average fossil-fuel electricity generation
efficiency = 0.328
Tt = U.S. average electricity transmission efficiency =
0.924
Tp = Petroleum refining and distribution efficiency = 0.830
C = Watt-hours of energy per gallon of gasoline conversion factor =
33,705 Wh/gal
Eg = (0.328 * 0.924 * 33705)/0.830 = 12,307 Wh/gal

My dad says his new corvette averages 30 mpg.He says the vettes of the future well be different to get 35 mpg,mabe smaller.i guess being sleek and light makes that v8 engine idle along.

Actually, ethanol is a lousey motor fuel for several reasons.First, there is the low BTU value which results in significantly lower mpg. It also soaks up water very readily from the humid atmosphere, making it even lower in BTU. It cannot be shipped in the same pipeline system as gasoline or diesel. And there is the questionable economics of using as much energy to make it as derived from it. Its saving factor is the huge political force driving it. Fermentation is an amazing process which can take various pathways. In fermenting mash for moonshine production, care has to be taken to exclude air from the vat to prevent formation of fusel oil. Fusel oil is an undesired by-product of fermentation which gives an off taste to the ethanol. However, fusel oil burns a lot better than ethanol and would be a better fuel. If fermentation can be redesigned to make fusel oil, butanol or other higher products, it would be a much better process for motor fuel. I think I read somewhere that BP and DuPont were looking at this. Cellulosic fermentation would be better than using food grains, but we don't have economical technology...yet. But the politicians have their blinders on and are charging full speed ahead. Please don't confuse them with facts.

Ethanol is a stop gap, it isn't a solution. It is and has been politically driven as a replacement fuel for gasoline since the 70s, in big part because of the politics of the midwest. Grain crops are an easily grown, low profit high production crop. The prices have been supported by government aid since the 30's because they are food staples, and prior to that (as well as in many countries today) there had been periods of bread shortages when production of grains fell short. The thing about food is we expect food staples to be cheap, as we believe an adequate supply is necessary to maintain society (This is definitely no capitalism). However, we allow fuel and energy to be expensive, as we have not yet decided politically that these are socially necessary for our society at the level food staples are. Thus the farming corporations, many of which are actually close family held corporations, can make much huger profits from growing crops for fuel production than for food, and these corporations devote large sums of money to midwestern politicians who will promote the development of ethanol production and use. This will also likely become a limitation on cellulosic ethanol once they gain enough market control and political posture, as cellulosic ethanol does not require corn or wheat, and could be made from any crop waste, expanding the market for raw ethanol materials and the cmpetitors these midwestern interests must deal against, driving thier prices back down.

Of course it must be noted that if the market were allowed to bear on the agronomic production of staple grain crops, production would stabilize at some level where it was competitive, and of course as in the period prior to 1930s, bread might not be readily available to all. Subsidies are going to be a problem in the future with such grain crops as we will need more oversight to make sure we are subsizing the food production, versus subsidizing food production that the grower sells under the table for fuel production and more profit, while still receiving subsidies.

Personally, I would prefer using food for people fuel, not auto fuel.

Use corn for food. After harvest, cut the stalks and use them to make ethanol.

Bill

It is only another path among many. The doom and gloom GW crowd and their Leftist political enforcers have pushed it too hard and to the exclusion of other paths. There are non-food crops that are better suited to ethanol production, but the farmers are stuck in corn mode. Crops to produce vegetable oil are possible. Some algaes can be grown in big tanks to make oil too. Coal can be processed into a very clean fuel. The waste products from the process can be solidified and buried in old coal mines. It is possible to genetically engineer plants that would grow on marginal land and produce either ethanol or oil.

The environmentalist extremists won't hear of any of it and they will pressure their leftist friends in government to stop it, because they really don't want people to have private transportation. There is no wrong path or right path, there are many ways to power a car and the government should keep out of the tax/fine and subsidy way of forcing political goals on the auto industry. Free enterprise will find a way. All government should do is protect start-ups from being unfairly crushed by the Big Companies. No subsidies or tax breaks!

Good Answer and very clear thinking. I suggest that you register so that you receive "credit" so to speak for your ideas.

Dragon

IMO, electric vehicles should be the best path. All stops should be pulled to develop the needed batteries. Electric is so much more efficient . The internal combustion engine wastes most of the energy in the form of heat. It is an obsolete technology.

I thought the using food for fuel was a bad idea right from the start.And all the smoke and mirrors about cafe and credits what a joke.Heres a few easier ideas,just reduce peoples love affair with pickup trucks by making them a commercial vehicle,if more folks drove vehicles that got say 30 mpg instead of like 12 mpg think of all the oil we would save.also i think electric engine accesories and engine stop technology for cars would help.offer people some sort of incentive to move closer to where they work,i drive for a living,all i see everyday is people driving pickups with knothing in the bed,as daily transportation(four wheel drive of course!)if your a trademan and really use a truck,well good,but thats not whats going on.to bad geo metros didnt catch on.

It's a good thing you asked this question about good student car insurance for you just might qualify for discounted rates. Are you getting good grades in school? Are you able to maintain an average of not lower than 'B'? If your answer is yes, then you should be able to enjoy such good-student benefits. You can ask your auto insurance provider about it.

Most insurance companies do give incentives on students who maintain a high GPA of 3.0 or an average not lower than 'B'. Students with high scholastic records could easily slash as much as 10 to 25 percent off their premiums. The higher your grades, the higher your chance of getting discounted rates. How about age? Usually, those who are 21 to 25 years old can enjoy these benefits.

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Bob