E85 and GM Flex Fuel

19828 Views 69 Replies 42 Participants Last post by razorlab, Jul 20, 2016

Malves85

Discussion Starter · Feb 29, 2012

I was talking to someone this week about the flex fuel vehicles by GM and found something interesting. This particular person owned a Buick. They informed me that with flex fuel they can add either E85 or regular gas to the car at any point in time and drive. There are sensors that measure the ratio of E85 to gasoline and make the proper adjustments to run the engine. This guy knows nothing about cars. This buick isnt modded and tuned up. Typical old financial guy that probably read this info somewhere.

I'm curious if this is actually true and if anyone has adapted the sensors to work with our car. I see these threads where people tune for E85 and can put nothing but a full tank of E85 in their car. If they want to use regular gas they have to empty the tank and retune the car. Thats just too much work for any sane person. According to this flex fuel info you can fill the gas anytime with either fuel and the sensors and ecu will adjust the engine.

Is this true?
How do we get it?
Also did anyone hear in the news that Exxon or one of the other big gas companies is investing a lot of money to farm algae? Supposedly it can be turned into fuel.

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razorlab

· #2 · Feb 29, 2012

Yes the true Flex Fuel cars are actually Flex Fuel. Imagine that.

The flex fuel mod for the evos on stock ECU are currently being worked on for evo 8 and 9.

Alot of us use the GM Flex Fuel sensors to measure the % of eth in our E85. Currently it only does that.

Some of the new Flex Fuel cars don't even have a Eth sensor, they do it off 02 sensor trim feedback.

DRIV4K16

· #3 · Feb 29, 2012

This is true that they can fill either or at any time, my friends dad has a flex fuel capable Avalanche.

Tye1

· #4 · Feb 29, 2012

That's a really good question! I didn't know that either about the flex fuel vehicles. I assumed they could only run E85 "OR" regular unleaded as well. To not have to worry about switching tunes when you get low on gas is a nice change! I'm not tuned for it at the moment but I would be all over the chance if someone made a reliable product that will work in the Evo's.

KickAss

· #5 · Feb 29, 2012

Yes, this is true. But those sensor kits are $$$. They weren't as cheap as I'd imagined them to be.

insane_DOHC

· #6 · Feb 29, 2012

KickAss said:
Yes, this is true. But those sensor kits are $$$. They weren't as cheap as I'd imagined them to be.

I was going to check the junkyards for those sensors. Could probably get them for a steal since the junkyards near me are operated by a bunch of goons.

PRORICAN

· #7 · Feb 29, 2012

There's a shop back in Houston using this on their cars from all out drag cars to street cars.
http://www.proefi.com/Pro_Flex_Fuel.html Its expensive though.

on2it

· #8 · Feb 29, 2012

would be cool if we had that!

Kracka

· #9 · Feb 29, 2012

razorlab said:
Yes the true Flex Fuel cars are actually Flex Fuel. Imagine that.

:yeahthat:

PRORICAN

· #10 · Feb 29, 2012

on2it said:
would be cool if we had that!

I believe you can. They were looking to try it on an Evo X so I called but the quote was way to high. Maybe they got some other X to try it on. I know they have drag Hondas, supras and evo 8/9 on it if I'm not mistaken.

bobby.is.rad

· #11 · Feb 29, 2012

Adding flex-fuel capabilities to cars and trucks is just a way for car makers to skirt CAFE MPG requirements and gas-guzzler taxes. 99.99% of people who buy a flex-fuel capable car will never use it. Lucky for us, they have corn pumps in a few places because of it.

Golden

· #12 · Feb 29, 2012

There are gas pumps that now let you select the % of ethanol you want for your flex fuel car. They say that ~40-50% is the best ratio for econ and $ per mile and power (in crappy stock flex fuel cars).

doibugu2

· #13 · Feb 29, 2012

Golden said:
There are gas pumps that now let you select the % of ethanol you want for your flex fuel car. They say that ~40-50% is the best ratio for econ and $ per mile and power (in crappy stock flex fuel cars).

What gas stations have that? Just wondering if it will be out by us soon.

Also, how high or low can you go?

X-Factor

· #14 · Feb 29, 2012

But I thought E85 wasn't as good as gas in terms of MPGs?

EvoX_luv2xlr8

· #15 · Feb 29, 2012

Good Info, My New Tahoe is Flex Fuel and wasn't to sure on this question.

Thanks for the info.

Stark Industries

· #16 · Feb 29, 2012

X-Factor said:
But I thought E85 wasn't as good as gas in terms of MPGs?

Its definitely not.

Also, I belive having a true "flex fuel" vehicle defeats the purpose of filling up with E85, and E85 only.

By itself its 105 octane. Mixed with a particular amount of 93 gas it wont be. The flex fuel idea would make tuning an absolute nightmare and detonation would certainly be present if you were tuned for E85 and had a majority gasoline mix during spirited driving.

There are test kits for E85 out there if you are uncertain of its purity.

Golden

· #17 · Mar 1, 2012

doibugu2 said:
What gas stations have that? Just wondering if it will be out by us soon.

Also, how high or low can you go?

Not sure which stations, but they have the pumps in Sioux Falls, SD. That city has E85 on just about every street corner.

razorlab

· #18 · Mar 1, 2012

The blender pumps depend on the company, station and state.

Here in California we have no blender pumps at all.

[email protected] Racing

· #19 · Mar 2, 2012

Even with the sensor wouldnt we need like 10 different tune setups installed for all the different fuel ratios? Sounds complicated when tuning a car for power.

Golden

· #20 · Mar 3, 2012

No, you would have 2 maps that the ECU would interpolate between depending on E%.

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