Demystifying E85 & Flex Fuel

On this Tech Tuesday we’re doing an in-depth update to an old video. We explain what E85 fuel is, what Flex Fuel is, and 5 truths you should know before converting your vehicle.

0:21 What is E85?
1:03 What is Flex Fuel?
1:18 What is the Stoichiometric value?
2:31 Truth 1: E-85 isn't available at every gas station
4:28 Truth 2: E-85 requires a tune every time you refill the tank
5:19 Truth 3: Modding your car for E-85 can be complicated
6:07 Truth 4: E-85 will add power on high-performance vehicles
7:23 Truth 5: Flex Fuel is not for everyone

Watch the other videos here:

Racing Fuels: C85 vs pump E85: Which fuel makes more power on the dyno?

ProFlex Commander by Advanced Fuel Dynamics: E85 Installation for 5.0 Mustang

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[german_i]

I had a 2007 Yukon with a flexfuel I ran E85 for 2 years without any issues. I now have a 2016 F150, and i bought it because it was flexfuel. It's been running great without any issues or the delay he claimed. I live in California. Regular gas is 4.99 a gallon and E85 is 2.98 a gallon so thats a difference of $115 dollars to refuel with regular gas and $60 with E85. I installed a scanner that can read the E85 rating and i have never gone below 77%. it gets me about 2-3 mpg less on E85 but even with the price difference its still cheaper to go with E85

[christophercleveland]

wow great video it help make a decision for my build coming up, the best video on e85 and the flex fuel tech so far!

[moustachio]

This might be my favorite car channel on YouTube

[InitialDIYmods]

Just an FYI, you did not explain the difference in stoichiometric values correctly. You stated that because it has a lower BTU content, you need more fuel to make power. Stoich value has nothing to do with the energy in the content in the fuel. If you combust both fuels at their stoich values, the energy released in the E85 will be lower and with a different energy release curve (e85 has a slower burn and higher resistance to ignition).
The correct explanation is because you have less energy during combustion after you reach the same lambda value, you need to add more air (and thus even more fuel) plus more timing to get more power. This allows you to access power that was previously restricted due to knock limitations based on engine design and operating conditions.
Still a solid video on e85, just that one bit that was miss-associated

[taylorgtrotter]

Stating that E85 needs a tune every single time you fill up is a bit of a misnomer. It’s a VERY forgiving fuel. As an example, in a carbureted application, you only need to change one jet size for every 5% change in the mixture. So if you have your carb square jetted with 94’s for e85, and then run a 80% fuel mix the next time you refuel, you drop one jet size to 93’s.

[genericdude]

I installed a flexfuel kit on my 2002 Mustang GT with stock injectors and fuel pump. And it's working fine with E85. I didn't do this for environmental concerns. I'm still testing it to see if it was a good investment.

[brettus]

PCMTEC software for us Ford users in Australia. Allows the use of flex fuel and to blend maps (fuel, ignition, boost) together...
Water/meth or lpg even if you wanted to I suppose!

[xGRMxREAPERx]

The Ford Mustang with 12:1 compression stock loves e85 and makes huge power on a flex tune. As long as your tuner unlocks that’s ability. You can watch the computer learn it after fueling up and it is very close and thousands and thousands of people run flex tunes and they work great? Not sure what you mean by bad and slow learning and rough running? Maybe older cars but 18+ mustangs work great and learn fast and add timing instantly after it learns

[jmend]

Have a nissan titan with flex from the factory. I have avoided it for fear of "lower grade" gas before. Honestly, just didnt know anything about it. Im going to try it out now on the titan!

[MIketucky]

90s 3800 v6. Just install 42lb injectors and go. Fill Up with E85 and enjoy the Supercharger.

[TheDude]

A consistent ethanol content is more likely to mean bad gas station. The reason the Ethanol content in E85 varies is because of the seasons. When its hotter you can run more Ethanol than when its colder. One of the reasons being that ethanol has a much bigger cooling effect than normal gas. When its really cold outside starting your engine with a high ethanol content might become quite hard.

[hayloss]

The bowser at the fuel station I go to (Australia) says "Always contains 85% ethanol"

[thenightangel]

My Holden SV6 has a badge saying SIDI with flex fuel written underneath. It's a 2012 model LFX Alloytec. I just put a tank of e85 in it. It definitely has more power. I normally just run 98 premium. I had to try it out though.

[jdoi]

Hurray for having flex fuel from the factory.

[bronzeageancientone]

Matthew Broderick knows a lot about cars!

[dannynewman]

Question. None ethonal fuel is pretty available in GA is that a good fuel to get a tune for on a daily driven/ track car for road courses and auto cross?

[dave]

I hope you can answer this question. I have an LS3 75 pound injectors, Pro Charge, big blower cam. Should I install a Continental Fuel Sensor and run E-85 and will this add HP to my set up? What are the risks and downsides to the above? Happy 4th of July. Where are you guys located in Florida?

[DingoZed]

Definitely a big price difference between setting up a fuel system for E85 vs pump. Having the mindset of wanting to use E85 because it’s cheaper rather the benefits of your setup is not the way to go.

[masoncampos]

So if I'm running a 6.0L and computer out of an 05 Escalade I can convert to flex fuel injectors and wire in the sensor to convert to E85 and the computer will not need to be changed?

[marklowe]

Question is, did Ferris run e85 in the Ferrari?