We have been hearing about E85 ethanol, or flex fuel, for the better part of a decade now. Depending on the climate you are in, E85 typically contains a blend of 85% ethanol and 15% gasoline. E85 was originally introduced to the mainstream market around the economic recession of 2008 as an alternative to fossil fuels that were skyrocketing in price at the time. Fast forward to today, and now more than 22 million flex fuel vehicles are on the road. While ethanol is less efficient (about 30% less) than gasoline due to the lower burn rate, E85 tends to be cheaper at the pump and has less of a negative impact on the environment than gasoline.
So what does it do from a performance aspect? Well for one, E85 is the perfect match for those seeking a high boost application on modern high compression motors due to ethanol's increased resistance to detonation. Similar to methanol injection, the alcohol content in E85 is a great aid in cooling down the incoming air/fuel charge, which is especially necessary in higher-heat forced induction applications. The cooler the air, the denser the air which equates to more power on tap.
Here's a great illustration of magic of E85 used in a high boost application. This is our 2016 Twin Turbo V6 Dodge Challenger on our in house dyno running both 93 octane and E85. Same vehicle, same boost pressure, but a significant bump in power with the ethanol over gasoline.
With use of E85 ethanol and appropriate tuning, we saw a net gain of 64 WHP & 38 WTQ over 93 octane gasoline! The gains do not stop there either, E85 enables the limits to be pushed to levels typically only seen with race gas!
Depending on how you use your vehicle, switching to ethanol may or may not be the right choice for you. Like we mentioned before, fuel economy does suffer and e85 isn't available everywhere like gasoline. Be sure to proper research ahead of time to determine if this is practical for your commute!