E85

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(Performance disadvantages of E85)
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*Prolonged exposure to ethanol corrodes many metal and rubber parts that are designed to be used with gasoline.
 
*Prolonged exposure to ethanol corrodes many metal and rubber parts that are designed to be used with gasoline.
 
*Use of fuel with more than 10% ethanol content will void most car manufacturers' warranties.
 
*Use of fuel with more than 10% ethanol content will void most car manufacturers' warranties.
*Water contamination of fuel is exacerbated by the presence of ethanol. Ethanol readily absorbs water but too much water cantamination will cause excessively lean fuel mixtures.  
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*Water contamination of fuel is exacerbated by the presence of ethanol. Ethanol readily absorbs water but too much water contamination will cause excessively lean fuel mixtures.  
*Air-fuel mixture problems. To achieve a usable fuel mixture, a lot more E85 is required. A carbureted car running E85 will need MUCH larger fuel jets than one running gasoline. Trying to run E85 with a carburetor designed and tuned for gasoline use will result in a very lean fuel mixture and a big drop in power. EFI cars will have similar problems. "Flex fuel" cars designed to run varying mixtures from straight gasoline to straight E85 have a fuel sensor in the tank line that can sense the proportion of alcohol content of the fuel. Thus the engine computer can adjust timing and fuel mixtures accordingly. Obviously other vehicles do not hanve any such capability unless heavily modified.
+
*Air-fuel mixture problems. To achieve a usable fuel mixture, a lot more E85 is required. A carburated car running E85 will need MUCH larger fuel jets than one running gasoline. Trying to run E85 with a carburetor designed and tuned for gasoline use will result in a very lean fuel mixture and a big drop in power. EFI cars will have similar problems. "Flex fuel" cars designed to run varying mixtures from straight gasoline to straight E85 have a fuel sensor in the tank line that can sense the proportion of alcohol content of the fuel. Thus the engine computer can adjust timing and fuel mixtures accordingly. Obviously other vehicles do not have any such capability unless heavily modified.
  
 
==Economic concerns from E85 use==
 
==Economic concerns from E85 use==
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*Ethanol runs at a richer air-fuel ratio, so you need to use more of it.
 
*Ethanol runs at a richer air-fuel ratio, so you need to use more of it.
  
===Carbureted engines===
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===Carburated engines===
 
*All fuel and air passages must be enlarged.
 
*All fuel and air passages must be enlarged.
 
*Many fuel pumps cannot pump E85 on an extended basis. Even the old diaphagm style pumps tend to suffer internal damage. Some seem able to hold up for years. There's no clear evidence of which ones last and which don't yet. Other than the electric racing pumps sold "for use with alcohol/methanol."
 
*Many fuel pumps cannot pump E85 on an extended basis. Even the old diaphagm style pumps tend to suffer internal damage. Some seem able to hold up for years. There's no clear evidence of which ones last and which don't yet. Other than the electric racing pumps sold "for use with alcohol/methanol."
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===Fuel injected engines===
 
===Fuel injected engines===
Feedback type fuel injection systems are idea candiates for using E85.  50% Larger fuel injectors are required, and an increase in ignition timing to compensate for the slower burning of the E85.  The feedback narrow band O2 sensor is a Lambda O2 and does not need to know what stoichiometric is, the sensor looks for the most O2 in the exhaust and the engine controller makes all the appropriate fuel calculations for the new fuel.  The larger fuel injectors and no engine controller modifications will prevent you from running dual fuel, as in gasoline OR E85, or a mixture of the 2.
+
Feedback type fuel injection systems are idea candidates for using E85.  50% Larger fuel injectors are required, and an increase in ignition timing to compensate for the slower burning of the E85.  The feedback narrow band O2 sensor is a Lambda O2 and does not need to know what stoichiometric is, the sensor looks for the most O2 in the exhaust and the engine controller makes all the appropriate fuel calculations for the new fuel.  The larger fuel injectors and no engine controller modifications will prevent you from running dual fuel, as in gasoline OR E85, or a mixture of the 2.
  
 
==Switchgrass==
 
==Switchgrass==

Revision as of 20:38, 24 September 2008

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