Had flexfuel engines not been somewhat mediocre, would ethanol be more widely accepted?
 

Much like a duck is able to walk, swim and fly while not being so remarkable in any of those, so is an average flexfuel engine when it comes to run on both ethanol and gasoline. But anyway, since flexfuel engines have been more frequently based on the less-sophisticated gassers of each manufacturer, maybe they could fare better if based on more advanced ones which could have parameters other than simply injection flow and ignition timing shifted on-the-fly according to the fuel in use to get better efficiency with both (or with various blends).

https://engineeringworkarounds.blogs...l-capable.html

Remember, up until recently, big auto wasnt capable on doing major" in drive " tuning. Not saying the technology wasn't there, just it wasn't in the cheap cars and the expensive cars the owner usually didn't care.

In 'Mericuh, driveability is a holy grail but not well defined.

I remember looking at 28¢ a liter for ethanol and couldn't do the math fast enough to see if it ws a cheaper fuel before going past the off ramp on the freeway. Next off ramp was generally 20 miles down the road.

Remember the way the US makes ethanol kind of sucks and is heavily department upon natural gas.

What do you propose for a more advanced design? What kind of fuel economy could be had for an engine designed to run only E85+?

We don't even have access to E85 in this part of the country.

The only way I'd be interested in high ethanol content fuel is if it's cheaper per mile than gasoline. Can an engine be engineered to deliver more miles per dollar on unsubsidized corn ethanol than gasoline?

I believe in order to run an efficient ethanol engine compared to gas, you really have to bump up the compression ratio into diesel territory. I think I've heard 14-17:1. Adjusting ignition timing and cam timing will only do so much. So, you can probably do this with a turbo or something that actually does alter the compression ratio like Nissan's VC-T technology.

Cummins did some experimenting on making a medium duty E85 engine. Pretty good read.

Cummins 2.8L E85 ETHOS Project

Can't find the full text of the study seems to have been removed from the web, it had technical specs on the full development.

Found reference to a 2005 study using E30 by the EPA with 1.9 liter engine with 17.5ish compression that got higher FE than E0 but haven't been able to find it.

Forget dedicated-ethanol engines, I wouldn't hold my breath not even for a return of them to the Brazilian market. When it comes to engine design, I consider the Toyota 8AR-FTS nearly perfect to be turned into a flexfuel engine.

OK, so what kind of fuel economy can be had from these engines, or more precisely, what does the BSFC look like?

If the engine can't put out, say 85% of the power of a gasoline engine by volume, then the ethanol-rich fuel wouldn't be economically viable in the US at current fuel prices. I'd also want to see the price of ethanol vs gasoline with all subsidies removed.

As I'm always saying, if something is better, it would be commonplace already (or will be very soon) without government subsidy.

The perfect engine for a flexfuel vehicle is direct injected and turbocharged. Variable boost on the turbo allows the engine to vary the effective compression ratio based on the blend of ethanol.


So why do flex-fuel vehicles suck so badly in the USA? The answer lies in CAFE (Corporate Average Fuel Economy). Manufacturers in the USA make flex-fuel vehicle to get CAFE credits. The manufacturer gets a 1.2 mpg credit for making vehicle flex-fuel. The fine for not meeting CAFE is $5.50 for every 1/10 of a mpg you miss it by. So a flex-fuel credit is worth $66. In order for it to make sense for a manufacturer to make a flex-fuel vehicle the cost has to be less than $66.

http://www.sdfu.org/assets/docs/uplo...19-17final.pdf


2011 Non FFV F150 3.5 ecoboost picked up 62 peak HP and 52 ft lbs torque using E30 of E10.

"Summary /Conclusions
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In all cases, non-FFVs tested on a dynamometer using splash blended E30 fuel provided greater horse power and torque based on data collected from idle to wide open throttle.
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Use of E30 in vehicles not labeled as FFVs reduced knock retard by 60% when compared directly to E10 in a six tank trial over 40 vehicles spanning in excess of 80,000 miles.
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Due to a reduction in knock retard, average mpg on the fleet of participants was not compromised. There was a gain in mpg on four cylinder vehicles using splash blended E30 vs E10. This is not consistent with responses previously reported in EPA certified lab testing using only certified fuels versus commercially available real world fuels.

Service vehicles were found to gain .4 mpg or 5.5% increase in mpg over 107,000 miles traveled on over 14,000 gallons of fuel."
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