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Lariat4x485
Mon, August 31st, 2009, 08:45 AM
Can someone tell me the difference between E85 and Gasoline??? I currently have a custom tune for 89 Performances. Is it better to get a custom tune for E85??? Thanks in advance....

cleatus12r
Mon, August 31st, 2009, 05:34 PM
You HAVE to get a custom tune for E85. Running E85 in a vehicle that cannot compensate for the MANDATORY decrease in air/fuel ratio will cause codes (P0171/P0174), lack of power (more than you'll lose just going to E85 with dedicated tuning), and driveability concerns.

E85 has a stoichiometric ratio of around 9.6:1. Gasoline's stoich ratio is 14.7:1. The engine control module is only able to compensate so much for a perceived lean condition.

It takes A LOT more E85 per unit of air to maintain happy operation than with gasoline parameters.

Is there any particular reason that you are wanting to run E85?

Lariat4x485
Mon, August 31st, 2009, 05:57 PM
Thanks, there is no particular reason i was just wondering what was the difference.