This is an old revision of the document!
When running a mix of ethanol and gasoline, you have to account for the difference in fuel makeup when calculating your global fuel adjustment. Some common numbers you'll need for this are provided below.
Fuel | Stoich AFR |
---|---|
Gas | 14.7 |
E70 | 10.6975 |
E85 | 9.8526 |
E100 | 9.0078 |
To calculate these values, use the following formula:
<% ethanol> * 9.0078 + <% gasoline> * 14.64
For example, for running pure E85, you would use:
0.85 * 9.0078 + 0.15 * 14.64 = 9.8526
The 14.64 figure above comes from the chemically correct stoichiometric ratio of gasoline. A lot more data can be found on the wikipedia E85 page.