Brand of Gasoline

[Cody Forbes]

Running a flex fuel on E85 is NOT the same as putting E85 in a "normal" car. A non-flex fuel vehicle is unlikely to run well or at all. Fays car would certainly have set a check engine light. E85 stoiciometric ratio is about 9.2:1 whereas gasoline is 14.5:1. This means that in order for the oxygen sensor to show stoic (or whatever ratio the ECU is looking for at any given moment) the car would need to add more than 30% more fuel by volume. Most (all that ive ever seen) OE EFI systems will turn on the CEL when the adaptation hits 25%. It's unlikely that the injectors have 30% worth of overhead so at high load it would run lean and misfire. The adaptation is also not instant. After filling with E85 the car would be constantly running lean and misfiring until it corrected enough. An accidental E85 fill up is not something that you suspect after getting bad mileage, it would be noticeable with drive ability problems almost immediately.

Flex fuel vehicles have relatively large injectors to facilitate running E85 and nearly all of them have a sensor in the fuel tank that measures ethanol:gasoline ratio and adjusts fueling calculations to get the right air:fuel ratio no matter what the ethanol quantity is.

-Cody Forbes

On Sep 20, 2012, at 8:56 PM, Grant Lenahan <glenahan at vfemail.net> wrote:

> That's E85 not E10/15  So your difference should be 8x what she could reasonably expect.
> 
> just to fact check - does everyone realize that E85 means 85% ETOH while normal gas is up to 10% typically - according to the stickers on the pumps here in sunny NJ and apparenyl 15% if specifically noted?
> 
> divide your difference by 8 and re-start.
> 
> Grant
> 
> 
> Grant Lenahan
> glenahan at vfemail.net
> 
> 
> 
> On Sep 20, 2012, at 8:36 PM, Steve wrote:
> 
>> I have a flex fuel Furd Escape and if I put in the E-85 I get about 16 mpg. Worse if I am doing a lot of city driving. When I use regular 87 octane gas I get 20-24mpg. The E-85 is 30-50 cents cheaper but it is not worth it IMHO.
>> 
>> So if I went 200 miles I would use about 9 gallons (22mpg) and 12.5 gallons of E-85. My "gotta-get-gas light" comes on after 13 gallons are used so in this case it would be nearly the same as what Fay encountered.
>> 
>> Could be wrong though. (Kids say I usually am)
>> 
>> 
>> 
>> 
>> 
>> --- On Thu, 9/20/12, cobram at juno.com <cobram at juno.com> wrote:
>> 
>> From: cobram at juno.com <cobram at juno.com>
>> Subject: Re: Brand of Gasoline
>> To: phixxitt at yahoo.com
>> Cc: quattro at audifans.com
>> Date: Thursday, September 20, 2012, 6:06 PM
>> 
>> Steve <phixxitt at yahoo.com> writes:
>> 
>>> I wonder if Fat has been filling up with E-85 gas and the last tank 
>>> was regular premium?
>>> 
>>> That would account for the price difference and mileage. 
>> 
>> I think you nailed it.  
>> Just a variation of the Diesel cars regularly brought into shops on a
>> hook because someone has filled the tank with gasoline.
>> 
>> 
>> BCNU,
>> Experience is the name everyone gives to their mistakes.
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> 
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