CAFE only counts the Gasoline not the ethanol.

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Originally Posted By: Garak
Perhaps a mention of it should follow every moral panic story the media publishes about VW/Audi.


100%+
 
Originally Posted By: Shannow
Originally Posted By: turtlevette
Yea, that's ghetto writing. How dumb do you have to be to think a 10% additive with 30% less energy content yields a 30% reduction in mileage. The guy's a punk.


What ?

gasoline, LHV 44 MJ/Kg, density 0.75, 33MJ/L
ethanol, LHV 26.9 MJ/Kg, density 0.785, 21.1MJ/L

36% less energy per litre...so firstly, you math is wrong.

In 85% concentration (you DID read didn't you before declaring hack, or is reading and comprehension failing too ?), resultant 22.9MJ/L...give 70% of the energy per litre.


So 30% mileage hit for 85% Ethanol is entirely thermodynamicaly reasonable




I get the stupidity of the calculation approach - probably made sense to someone polysci major whose highest math was in high school...

But are we looking a bit too much apples and oranges when talking fuel energy content? I thought the latest engines could retune and make a lot more power and in turn better efficiency when running on ethanol? The gm 4.3 comes to mind.

Doesn't equate to the mpgs from the gasoline component ridiculousness, but there may be something beyond just that the energy contents scale mpgs as a weighted average.
 
From wiki:
However, the total increase in a manufacturer's average fuel economy rating due to dual-fueled vehicles cannot exceed 1.2mpg.[24] Section 32906 reduces the increase due to dual-fueled vehicles to 0 through 2020. Electric vehicles are also incentivized by the 0.15 fuel divisor, but are not subject to the 1.2 mpg cap like dual-fuel vehicles.



So, the idea that a Tahoe gives a crazy high CAFE mpg is more complicated and goes away in 2020.
 
Originally Posted By: shanneba
Keep in mind E85 may have anywhere from 53% - 83% ethnanol.

http://www.afdc.energy.gov/fuels/ethanol_e85_specs.html
D5798-11 Standard Specification for Ethanol Fuel Blends
for Flexible-Fuel Automotive Spark-Ignition Engines

Ethanol Content, vol% D5501 51-83
Methanol, vol% D5501 0.5, maximum


That is quite true. But also that E10, 10% is the maximum and most would not contain near that. Same situation. It is very probable that most E10 is probably E5- E8 in reality. This is the same thing regarding diesel fuel. The sulfer content must be no more than 15 ppm for ULSD. When tested, most diesel in considerably below that. For the same reasoning. To avoid the risk of going over the limit, the level is reduced. So it would be safe to assume the same for E10.
 
Originally Posted By: turtlevette
Originally Posted By: Shannow
Originally Posted By: turtlevette
Yea, that's ghetto writing. How dumb do you have to be to think a 10% additive with 30% less energy content yields a 30% reduction in mileage. The guy's a punk.


What ?

gasoline, LHV 44 MJ/Kg, density 0.75, 33MJ/L
ethanol, LHV 26.9 MJ/Kg, density 0.785, 21.1MJ/L

36% less energy per litre...so firstly, you math is wrong.

In 85% concentration (you DID read didn't you before declaring hack, or is reading and comprehension failing too ?), resultant 22.9MJ/L...give 70% of the energy per litre.


So 30% mileage hit for 85% Ethanol is entirely thermodynamicaly reasonable




We keep having the same arguments over and over. You assume 100% conversion efficiency to energy. Ethanol is more efficient.
I'm having a little trouble with the notion that a fuel can have a greater than 100% conversion efficiency into energy.
 
Originally Posted By: Shannow
Originally Posted By: TiredTrucker
I sense trolling....


He's known for it...

Considering the original post, that for CAFE purposes only the gasoline component is considered, saving the auto makers $Ms.

Given that when they spec a lower viscosity engine oil, and must make every attempt to prevent the owner from going thicker (backsliding rules), how on earth are they going to stop flex fuel owners from filling with whatever they want/can get on the day ?

It's pretty silly to give them the CAFE credit for producing a flex fueler, while acknowledging that the owner can fill up with anything on the market.



I am for anyway to circumvent the regulations, legally. Be it my commercial truck or an OEM auto maker. If making flex fuel vehicles at only about $100 more per vehicle to do so, and circumvent CAFE standards, I applaud that! The consumer market should be the only dictate on fuel economy and vehicle choices. Folks vote with their wallet which promotes advancing technology much more efficiently than government mandates.

I saved roughly $40K over the cost of a new production semi truck with a new emission laden motor by buying a new truck without a motor and dropping in a factory rebuilt pre-emission motor. It was a loophole in the EPA and IRS regulations that I took advantage of. My purchase cost was lower, and my operation cost is significantly lower than buying one of those new emission motors. The fact that the OEM is able to use similar techniques to circumvent CAFE standards, more power to them. We are over regulated at every turn. So much so, that the agencies themselves are not aware anymore of all their own regulations. Hence, me being able to pull off what I did right under their own nose.
 
So my big wonder, if it truely is only $100 differce to the manuf between flex and non flex vehicles, And if they truely get a better score towards their cafe fleet numbers, why not just make all their vehicles flex fuel? Why make 2 different versions of the fuel system for the same model/engine?
 
You would have to ask them. There is usually always some method to the madness that motivates entities to do what they do. It really can't be any secret that most flex fuel capable vehicle owners do not take advantage of that at the pump. It may be a percentage game they are playing as part of the process to come in under the CAFE radar. And they aren't talking. It may not actually be a $100 cost to change anything to make a flex fuel vehicle. That is what the OEM claim is. I contend it costs them nothing. They pretty much use the same components for all vehicles in a model line up. Only ECM programming changes. Having hauled production auto components and parts to auto plants for years, I learned it is cheaper in cost and logistics to reduce the component smorgasbord and consolidate differences and spread the overall cost across the product line.

If I can spec full lockers in drive axles on my semi when it is produced for only $85 an axle on a special order outside the normal design specs on a commercial semi truck, it is difficult to convince me that it costs an OEM $100 a vehicle to make it flex fuel. To simplify logistics and component manufacturing, most everything they need to put in a vehicle to make it flex fuel is also what is put into every vehicle they make since they are factoring flex fuel as a part of normal production and in high volume.
 
Originally Posted By: Shannow


Are you claiming over 100% efficiency for ethanol ?

I seriously hope not, but that's the basis of your argument there.


You take things too literal. Use your filter. Energy conversion can't exceed 100%. Come on. You assume equal conversion rates. Ethanol ends up being higher because you can lean it out at cruise and get better efficiency. It runs cooler so it can be run leaner. I got about the same mileage using e85 in the vette. I believe many observe higher mileage than what you calculate. Here we go again with your formulas from engineering tool box. Things are not as straightforward as you think. Its like your .25 HP calcs for the engine oil pump. A good engineer looks at something like that and thinks "that can't be what else is going on here". Inexperienced green engineers or wannabes blindly trust the output of a formula or computer program. That has caused some engineering disasters. I believe you've already admitted to an under sizing of a thrust bearing lift pump.
 
Originally Posted By: TiredTrucker
... It may not actually be a $100 cost to change anything to make a flex fuel vehicle. That is what the OEM claim is. I contend it costs them nothing. They pretty much use the same components for all vehicles in a model line up. Only ECM programming changes. Having hauled production auto components and parts to auto plants for years, I learned it is cheaper in cost and logistics to reduce the component smorgasbord and consolidate differences and spread the overall cost across the product line.

If I can spec full lockers in drive axles on my semi when it is produced for only $85 an axle on a special order outside the normal design specs on a commercial semi truck, it is difficult to convince me that it costs an OEM $100 a vehicle to make it flex fuel. To simplify logistics and component manufacturing, most everything they need to put in a vehicle to make it flex fuel is also what is put into every vehicle they make since they are factoring flex fuel as a part of normal production and in high volume.


slightly more than ECU programming, there's a Flex Sensor that has to go in the fuel line to determine the ethanol content so the ECU can compensate. and i highly doubt that in the scale of a full production run, those sensors would cost them anywhere near $100 each.

what really boggles me is not making Boosted(Turbo/Supercharged) vehicles Flex Fuel. an engine that could make serious use of the Higher Octane rating of the ethanol...
why Ford Doesn't automatically make all Ecoboost engines Flexfuel capable is just beyond me.
 
Originally Posted By: turtlevette
You take things too literal. Use your filter. Energy conversion can't exceed 100%. Come on. You assume equal conversion rates. Ethanol ends up being higher because you can lean it out at cruise and get better efficiency. It runs cooler so it can be run leaner. I got about the same mileage using e85 in the vette. I believe many observe higher mileage than what you calculate. Here we go again with your formulas from engineering tool box. Things are not as straightforward as you think.


I was using the energy of a tankful as a starting point...that's sound.

I linked to an Aussie test where they drove the same roads with gas and E85 (and E10)...you ignored it.

Here's an American test.
http://www.edmunds.com/fuel-economy/e85-vs-gasoline-comparison-test.html
26.5% worse mileage, on a dedicated flex fueler. 22% more cost per mile on E85.

Here's the Government's take on it...
https://www.fueleconomy.gov/feg/flextech.shtml

15-30% depending on vehicle...I can get the 15, due to the factors that you state, 30% plain old dumb tuning that can't take optimum benefit.

I looked at the Ricardo documentation (which was what I was looking for in the first instance), they claim "diesel like efficiency"...efficiency being energy output over energy input, then clearly even the Ricardo miles are limited to a percentage of the energy content in the tank...less energy in tank and same "diesel like efficiency", equals less miles...clearly.

But, you are the turtle...and if your corvette gets as good or better MPG on E85, then you need to talk to GM, the Government, and especially Ricardo (some of the greatest minds in IC engines)...you, my boy are going to be very very rich.
 
Originally Posted By: earlyre
slightly more than ECU programming, there's a Flex Sensor that has to go in the fuel line to determine the ethanol content so the ECU can compensate. and i highly doubt that in the scale of a full production run, those sensors would cost them anywhere near $100 each.

what really boggles me is not making Boosted(Turbo/Supercharged) vehicles Flex Fuel. an engine that could make serious use of the Higher Octane rating of the ethanol...
why Ford Doesn't automatically make all Ecoboost engines Flexfuel capable is just beyond me.


Agreed, but they are thinking out 60k miles or more and probably worrying about reliability issues.

Conservative timing is what keeps engines together even with poor fuel. Run everything out at the ragged edge of reliability for efficiency and you could end up with a LOT more warranty claims...
 
Originally Posted By: SteveSRT8


Conservative timing is what keeps engines together even with poor fuel. Run everything out at the ragged edge of reliability for efficiency and you could end up with a LOT more warranty claims...


Well the current systems can detect knock and retard before the next plug fires. Its the height of slimebaggery for OEMs to claim they can't handle E15. If the govmt wasn't around to push technology, we wouldnt have half of what we do. The technology is there.
 
Originally Posted By: turtlevette
You take things too literal. Use your filter. Energy conversion can't exceed 100%. Come on. You assume equal conversion rates. Ethanol ends up being higher because you can lean it out at cruise and get better efficiency. It runs cooler so it can be run leaner. I got about the same mileage using e85 in the vette. I believe many observe higher mileage than what you calculate. Here we go again with your formulas from engineering tool box. Things are not as straightforward as you think. Its like your .25 HP calcs for the engine oil pump. A good engineer looks at something like that and thinks "that can't be what else is going on here". Inexperienced green engineers or wannabes blindly trust the output of a formula or computer program. That has caused some engineering disasters. I believe you've already admitted to an under sizing of a thrust bearing lift pump.


Wow.

I think that post is a new standard for you.
 
Originally Posted By: earlyre
Originally Posted By: TiredTrucker
... It may not actually be a $100 cost to change anything to make a flex fuel vehicle. That is what the OEM claim is. I contend it costs them nothing. They pretty much use the same components for all vehicles in a model line up. Only ECM programming changes. Having hauled production auto components and parts to auto plants for years, I learned it is cheaper in cost and logistics to reduce the component smorgasbord and consolidate differences and spread the overall cost across the product line.

If I can spec full lockers in drive axles on my semi when it is produced for only $85 an axle on a special order outside the normal design specs on a commercial semi truck, it is difficult to convince me that it costs an OEM $100 a vehicle to make it flex fuel. To simplify logistics and component manufacturing, most everything they need to put in a vehicle to make it flex fuel is also what is put into every vehicle they make since they are factoring flex fuel as a part of normal production and in high volume.


slightly more than ECU programming, there's a Flex Sensor that has to go in the fuel line to determine the ethanol content so the ECU can compensate. and i highly doubt that in the scale of a full production run, those sensors would cost them anywhere near $100 each.

what really boggles me is not making Boosted(Turbo/Supercharged) vehicles Flex Fuel. an engine that could make serious use of the Higher Octane rating of the ethanol...
why Ford Doesn't automatically make all Ecoboost engines Flexfuel capable is just beyond me.


True, it does require an additional sensor. But I can get that sensor easily for $100. As a production component being installed on the line in an assembly plant, I would bet it is only 1/4 that cost, if that. Just like any other volume buyer, there are substantial discounts and negotiated contracts for parts that go into regular production assembly that you as an individual will never get for pricing.

I have also wondered why the OEM's haven't fully taken advantage of the full potential of something like E85.
 
Originally Posted By: turtlevette
Its the height of slimebaggery for OEMs to claim they can't handle E15.

I will agree with you on that. If they can crank out flex fuel E85 vehicles, then E15 should not be a problem. But, it makes a nice focal point for OEM grousing. Look at OPE. I had work done and the guy does the usual, "Yep, that's what ethanol does to these things," speech, then told him it never had a drop of anything but pure gas. Eighty cent fuel systems aren't at fault, you know - ethanol is.
 
Originally Posted By: turtlevette
Originally Posted By: SteveSRT8


Conservative timing is what keeps engines together even with poor fuel. Run everything out at the ragged edge of reliability for efficiency and you could end up with a LOT more warranty claims...


Well the current systems can detect knock and retard before the next plug fires. Its the height of slimebaggery for OEMs to claim they can't handle E15. If the govmt wasn't around to push technology, we wouldnt have half of what we do. The technology is there.


Actually it's the FAILURE of such technology that concerns them. We can't all drive vehicles with state of the art tech, we drive vehicles with proven reliable tech that someone guarantees.

And BTW, many vehicles are much faster than you suggest right now. Mercedes has a newer engine that can strike, sense, and re-strike again and again before the combustion event has even ended. That is not the reason they don't advocate for a political solution to gasoline.....
 
Originally Posted By: SteveSRT8
That is not the reason they don't advocate for a political solution to gasoline.....


A double negative.

Real car guys want to burn alcohol to go faster. We don't care about politics of it. OK some farmers are making some good money. So what? Anything can be politicized.
 
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