Date:         Mon, 7 Nov 94 16:28:17 PST
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         Dave Kautz <dkautz@hpsidms1.sid.hp.com>
Subject:      Re: Ethanol

> 
> Dave Kautz writes:
> > 
> > > David Carment writes:
> > 
> > > A Gas company up here in Ottawa has Ethanol blend at the same price as
> > > regular. I asked him if it was good for air cooled engines and his answer
> > > was it has 15% higher octane, runs cleaner and cooler. Any opinions,
> > > advice, experience with using ethonal blend  for air-cooled Vanagon engines?
> > > 
> > > BTW its 55 cents CDN per litre up here.....DC 
> > > 
> > > ----------------------------------------------------------------------
> > > There was an interesting article in _Porsche Panorama_ about oxygenated fuels
> >   about a year ago. On vehicles with oxygen sensors, very little changes 
> >   except fuel mileage which drops (there's less heat available in Ethanol). On
> >   vehicles without O2 Sensors, exhaust emissions were shown to drop along with
> >   driveability and fuel economy. The air to fuel ratio for ethanol is different
> >   than that for gasoline (numerically lower) so unless one can richen up their
> >   mixture the engine effectively runs lean. 
> > 
> >   There was also considerable discussion of the corrosive nature of the 
> >   oxygenators. Although not as bad as methanol, Ethanol is more corrosive
> >   than gasoline. The article suggested using gasoline containing MTBE (Methyl
> >   Tertiary Butyl Ether???) because it is less corrosive but I have not been 
> >   able to find a gas station employee yet who could tell me what their      
> >   company was using as an oxygenator. The article said that ethanol smells
> >   sweet and MTBE smells like formaldehyde. I think all gasoline smells like
> >   sh*t, so I haven't followed this up.
> > 
> > 
> >   Dave Kautz
> >   '74 Westfalia
> >   sh*t. 
> > 
> 
> This is interesting and paradoxical, since we normally associate a leaner
> running engine with higher fuel economy. But if I understand you
> correctly, the engine will run leaner with Ethanol AND fuel consumption
> will also increase. Is this correct? This plus the potential corrosion
> could spell trouble, yes? DC -- 
> 
> ----------------------------------------------------------------------
> David Carment
> School of International Affairs
> Carleton University
> Ottawa, Ontario
> K1S 5B6
> voice - (613) 788-2600-6662
> fax - (613) 788-2889
> Email address: dcarment@ccs.carleton.ca
> ----------------------------------------------------------------------
> 
 If one was to switch from 100% gasoline to 100 % alcohol on a carbureted   
 engine, it would be necesary to install giant size jets because the air/
 fuel ratio for a combustable mixture is so different (about 10:1 for alcohol
 as opposed to around 16:1 for gasoline). Drag racers and high performance 
 powerboats sometimes run alternate fuels so that they can run outrageous 
 compression ratios without detonation, and they're not concerned about fuel
 consumption. When you mix the fuels, your engine wants an air/fuel ratio 
 that is a compromise - An oxygen sensor equipped engine adjusts the mixture
 until the exhaust gas is right. Other vehicles march on with mixtures 
 that assume gasoline and run like they are lean. This doen't explain why
 gas mileage gets worse, as you pointed out. The reason gas mileage goes down
 is because there is less energy available, per unit volume, in the fuel. To
 get the perfornmance you expect, you have to open the throttle further.
 Our friends with gag, gag, cough, hack diesels would like us to believe that 
 their engines are just way more efficient than gas engines (and they are more
 efficient) and that's why they use less fuel, but that's not the whole story.
 Diesel fuel is the opposite of ethanol, it has more energy per unit volume than
 gasoline. There's just more zip per drop in the fuel itself.

 Hope this helps. Given a choice, I'd stick with straight gasoline.

 Dave Kautz


 to around 16:1)