Re: Thoughts on ethanol-free gasoline?opr
Posted: Thu Dec 05, 2013 12:08 am
I would agree with your 'designed by committee' suggestion if it applied to engines actually tailored to run mixed fuels (rather than kludged to game a renewable fuel standard). But that's not what I'm talking about.TomT wrote:Sorry, but that is simply not true. Turbo and Super Chargers can accomplish many things but changing the mechanical compression ratio - which is just an important as the dynamic compression ratio - is not one of them... Engines optimized for high ratios of Ethanol (E85) also use different cam timing and duration profiles, and different lift. Then there are the different injector patterns and ignition requirements... An engine designed to run on both is, by nature, like a camel designed by committee; a compromise.
Unless I had no other options, I would never fuel anything I owned with E15... Thankfully, it appears as if it will never gain traction in the marketplace (and even the EPA is back-pedaling on it) so that likely will not be a consideration...
AndyH wrote:Yet the engines do exist - and modern computer controlled turbo- and superchargers and other tricks to change compression on the fly make it much easier today than yesterday. It's not rocket science - it's been done for years.
We've had the ability to vary valve timing, duration, and lift, as well as injection profiles and compression ratio since at least 2009 - here's one example:
http://www.gizmag.com/ebdi-ethanol-engi ... ncy/10929/
There are plenty more - gas and diesel:
http://www.nissan-global.com/EN/TECHNOL ... W/vcr.html
http://www.sciencedirect.com/science/ar ... 0412003020
Your suggestion that the "EPA is back pedaling" on ethanol is also incorrect. Yes, they reduced the renewable fuel production level for the coming year - but that is not the same as reversing a decision. The renewable fuel standard is a production requirement. Other laws define the legal volume of ethanol in gasoline (E10, E15, E85, etc.). Our gasoline demand has dropped - so the production target must drop as well.
As for E15? The EPA isn't changing course - but they are getting beat about the heads and shoulders by the oil industry and their sycophants (like the AAA).