That would be a nighmare of the worst kind. However, the point was, of course, the EPA did such a WONDERFULLY ACCURATE job of estimating fuel mileage on new vehicles.


Hmmmmm. Looks to me like you just did.




Great, so all I have to do is to bump up the compression on my engines. Now where IS that pesky "Compression Adjustment Screw" located? Under the carb? On the intake manifold? OOOOOOHHHHHHH, I have to go through a major overhaul, shave the deck and heads and step up to custom, taller pistions? Great. What's that gonna cost? 50 bux? 100? What do you mean $3000 to $6000????? Well THIS deal is looking better all the time!!!!!

Point is, I have several cars in perfectly good running order that I can spend a grand total of ZERO$$$ on and run gasoline in them for a LOT cheaper than I could convert to a new fuel. Thanks, but no thanks.

 

Eh, political issues were already brought up, in the form of subsidies and taxes. Which, BTW, I would have thought the moderator would have done something about. At least I admit that they are political issues when I use them for my argument. Since the issue seemed open, I took advantage.

Nobody's asking you to do anything! If you like running gas, and it's working for your wallet, then by all means, go for it. I'm not suggesting that everyone go out and pop high compression pistons and bigger fuel injectors in their grocery getter, just so they can run E85. That's why they call it Ford Truck Enthusiasts, not Ford Truck Drivers. It takes a special kind of person to want to optimize something. An enthusiast. Someone who's not afraid to take risks. Be it higher performance, bigger cams, or different fuels. It's all a fun, rewarding activity. If we, as enthusiasts, want to mess with this stuff, what do you care?

My 11:1 4.0L V6 that I'm almost done building is not costing $3000. More like $1500. Will I recover that in fuel costs? Maybe, maybe not. But I am certain it will get good mileage on the e85 it will be running, and will make a whole lot more power. I'm having fun, and that's what counts.

 

How much to hire it done?

 

Now why would I want to do that? Weekends are plenty. OBTW, that $1500 includes all machine work. Like I say, it's not for everyone. If it was easy or simple, everybody would be doing it! But that said, not everyone builds a motor either. Even fewer build it up differently than stock. But if you are rebuilding, the whole high compression E85 thing adds some fun to it.

 

You answered your own question.

 

So, because I like numbers, the way I see it:

1: Cost of my labor: We'll say $0.00 (I'm cheap, but I'm not easy)
2. Cost of rebuild: $1500.00
3. Potential savings of Ethanol over 100% gasoline: $1.00 per gallon
4. Potential loss of gas mileage from ethanol over gasoline: 10%
5. Final savings per gallon: $0.90
6. ROI of $1500.00: 1666 gallons of gasoline used to make break even. (BEST CASE SCENERO fuel mileage is identical, no loss for E85, break even point is 1500 gallons.
7. Average mpg for a truck, because we are in a truck forum: 13mpg
8. 1666 gallons time 13mpg: 21,658 miles
9. Most pickups aren't an only commuter; thus run about 7000 miles a year: ROI is 3 years

And I now have a vehicle that probably won't run all that well when I go to an area that doesn't have E85. Instead the highest they have is E10. But even if the fuel was available, other than for the pure fun of tinkering with your vehicle, there is practically no common sense, from a financial position, for doing such a modification.

Then again, if I believed that ethanol was indeed better for the ecology and environment, then I'd personally be will to pay a little extra to convert. But, ethanol hasn't proven to be that good for the environment. In many studies, it's possible that ethanol is as bad or worse for the environment than gasoline is. But, from a financial position, I don't believe that a 3 year ROI is worth it to me. For the fun of tinkering however: PRICELESS. Later... Mike...

 

Contrary to popular belief, the efficiency of an internal combustion engine does not directly depend on fuel. The alcohol engine used in the above study were most likely not street legal. One reason why gasoline engines didn't get much better lately is the EPA mandate on NOx emission.

 

And what question would that be?

Christcorp, you've proven my point. You'd break even relatively quickly, especially if you drive more miles a year, plus you'd have a newly rebuilt higher performing motor the whole time. That's got to be worth something.

As for finding fuel, it's E85 or nothing. Not being able to run gasoline, at all, is one downside I admit. But it's not like E85 is hard to find, especially around here. See:
http://www.e85refueling.com/ Everywhere I typically go with the Explorer, I'll be covered. For me, not a problem. For others, well, do your homework!

 

The efficiency of the engine itself doesn't depend on fuel necessarily, like you said. Overall efficiency is the work energy out of the engine over the fuel energy into the engine.

Engine thermal efficiency depends a good deal on compression ratio, which ethanol can tolerate more of without harmful detonation. But, like you said, with the higher compression ratios come higher combustion temperatures and higher NOx emissions. I don't know that gasoline engines can get much higher on the compression ratio than they already are (at least the cars pushing 11.5 or 12:1). If less fuel is burned overall for that higher compression because the engine is operating more efficiently, what does that do for the net NOx emissions? If the increase of NOx emissions is 20% (purely hypothetical) with the higher compression ratio, but 20% less fuel and air is consumed, would the net NOx emissions remain constant? There's a trade off for everything it seems...

 

I'm not sure that I could agree that a 3 year ROI is considered "relatively quickly". If you were buying a new vehicle, then getting one that is already E85 capable seems more cost effective. Having a 4-10 year old vehicle, and investing the money into it, isn't necessarily a good financial move. Especially with the negative side of ethanol to the environment and human health still being debated. But strictly from a financial standpoint, about the time there is a break even, you might be trading in the vehicle anyway. I could however see a new vehicle with it factory installed. As far as E85 being readily available, it isn't that available. Not everywhere. In my state for instance, there are only 5 stations offering E85 in the entire state. 2 of which say "Soon". Not really an option if you have to drive 100+ miles to get gas. Later... Mike....

 

But that's also indirect It's only 'delta T'....

And they still have to employ EGR and other emission related crap to be legal here. In Europe, normal is around 92 octane while super is around 100 -- obviously, NOx isn't as high on their agenda.

It's not that simple because NOx production is non-linear.

I think VW is trying to get approval of a car with ammonia (NH3) injection to combat NOx -- instead of using lower combustion temperatures or catalyzers to break up NOx, that would bound it to harmless salts.

 

I know what I posted earlier certainly isn't an exact science, I just wanted to put forth something else to think about...

 

Yet people spend $$$$$ on new cars to get better mileage. Probably about the same break-even point there. If you're trading from a full size truck to a compact car, maybe, but that's an awful large initial investment to overcome with fuel savings.

On NOx:
Ethanol burns cooler than gasoline, as well as cools off the intake air more, so increasing the compression ratio wont have as much of a negative impact on NOx as an engine running gasoline. To what extent this helps though, I have no idea.

 

Increasomg compression is one of the most obvious way to increase thermal efficiency, but what you end up doing is increasing the spread between T-max and T-min (T = temperature) .

 

Right on, thermo and internal combustion engines was just a couple years ago for me, so it's somewhat fresh, even though I'm sure I've forgotten a lot of it.