Tammer in Philly wrote:altus22 wrote:It does have a higher octane rating, but remember, it has a lower energy density which means that you have to put more ethanol in to get the same power out.
Which means lower gas mileage. In addition, ethanol is still a net-negative energy source, meaning you expend more energy from hydrocarbons making EtOH than you get out of the EtOH when you burn it. Sweeney, pure (absolute) ethanol is hygroscopic, so the SAAB engineers were probably working with essentially 95% ethanol. But you knew that. What I'm curious about is the potential damage of water on fuel system components (thinking mostly corrosion here). Even in E85, increased water miscibility is a cause for concern.
-tammer
I am far from being any kind of environmentalist, but here's my interest in E85
1) cheap race gas
2)
decouples cars from foreign oil
3) doesn't drastically change how cars are made, run, or "feel" (as compared with a Prius or something that is an ugly, uninspiring slug of a vehicle)
Let me explain #2 a bit more. In software design we talk about decoupling a lot because we are bad at predicting change, and tight coupling makes changes expensive later. Adding indirection gives you flexibility and gives you opportunities to make improvements surgically without affecting the overall stability of the system
So how does that apply here?
Today, cars are coupled directly to gasoline. Nobody knows of a scalable way to make gasoline apart from fractionally distilling it from imported crude oil. Making gasoline is expensive in terms of the specificity of the resources required, the actual costs of acquisition and refining, and the less tangible costs of foreign oil dependance and continued involvement in the middle east. Without getting into all the details, let's just agree that if we had an attractive alternative to gasoline, we'd use it.
Gasoline is a pretty specific thing.. the more specific a thing is, the fewer obvious ways there are to create it.
Now, ethanol.. ethanol is a much more fundamental chemical than gasoline is. If we change the game so that vehicles are running on ethanol - even though that ethanol is
made from gasoline
today, we've bought ourselves some future flexibility.
Just like in software, flexibility and coupling come at a price - usually efficiency. So by moving to E100 or E85, we've bought some flexibility (cars are now insulated from gasoline, and are instead coupled to Ethanol, a more general concept), but we've lost some efficiency (today, it is arguably a net energy loss to run american cars on american made E85)
Now, while today E85 might not be more efficient than just using the fossil fuels directly, we know that there are other ways to make Ethanol (i.e. sugar cane waste-products).
Because ethanol is a simpler chemical, and because we've seen demonstrations of this, we should be convinced that it will ultimately be cheaper and easier to make ethanol than it will be to continue to make gasoline.
So while today, E85 production in the US is inefficient, don't count it out. Once there is a market demand for E85, people will figure out how to make it cheaply and efficiently, and eventually the work we did decoupling our cars and thus our country from foreign oil will have paid off.. even though we don't know what that ultimate solution will look like today.. we still know that decoupling cars from gasoline is a good move..
Matt
Agile Software Developer
