E85 in the 4.3 Ecotec3, Yes or No?

[Grumpy Bear]

There is a device in the fuel line between the tank and motor that 'reads' the alcohol content on a continuous real time basis. This device communicates that information to the PCM on a continuous real time basis. Adjustments are made on a continuous real time basis. It's not a batch or by the tank system. It's what gives the motor the ability to use FLEX FUEL. There is nothing special about the motor itself. 

 

E85 fuel has a variable alcohol content. GM's numbers for hp. and torque are based on a "certified E85". That is certified to be 85% by volume. Says so right in their own literature. Never happens at the pump because by ATF rules the blend ethanol is denatured with 2% distilled mineral spirits. (gasoline) Max is 83% by volume. E85R, what it was tested on isn't subject to the ATF rules and isn't available at the 'pump. Is available from SONOCO. (and a few others)

 

BOTH power and fuel economy are subject to the 'real' alcohol content of the fuel and not some number typed in a manual somewhere in your glove box. The 'tune' for any give content is an interpolation of base maps based on measured alcohol content. Nothing in you motor measures octane. But it can sense 'knock'. 

 

It being economical or not is a function of the math based on current reality and not subject to opinion. You cant' guess it or wish it you have to measure it. 

[swathdiver]

4 hours ago, tim5779 said:

Nevermind, I found a thread on here.  A refueling event consists of:

 

- Truck key must be turned to OFF during refuel

- No less than 3 gallons

- Allow 7 miles for truck to make calcs

 

Good to know.

That's funny, mine says you do not have to turn the engine off but check your local laws blah blah blah.  I can count on one hand how many times I've refueled with the motor off in thirty years, like almost never unless checking things under the hood.

 

Marty is right, here in Florida we have no idea what the alcohol content is beforehand and that it is not even likely to be close to 85% anymore.  I've had as little as 52% and now 71% but even with my BlackBear tune, the motor put out 302 rear wheel horsepower through the traps with the 52% FlexFuel.  I'll run it again after this bad cat is replaced and put on tie rod sleeves for 4WD launches.  Doggin' it I've gotten as low as 8 mpg and up to 15 and change, 14.7 mpg @ 75 mph.  Hard to develop a mpg pattern as the cat is getting progressively worse.  When the stuff is cheap, it costs $.16 cents a mile to run the truck and when they jack up the price its almost as much as 93, $.23 cents a mile. 

[Frank-OH]

The op's 4.3 is an exceptionally capable motor and can out perform many of the V8's that pre-date this version.  I most recently came from a vortec 5.3 to a ecotec 4.3 and the transition was seamless.  The new ecotec 5.3 is a more powerful engine but this doesn't make the 4.3 less capable as a truck engine.

Your right Donstar I wasn't trying to insult the op's truck it's a damn nice rig! I was just sayin that the new 5.3 is just about the perfect balance for a truck these days as far as mpg and tow/haul ratings and power, as I haul an tow a good bit but not enough to justify a Dmax.

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[tim5779]

So I waited until I was on E, because I wanted to experience the most drastic change as possible.  I filled up last night on the way home from work using E-85 at ethanol content of 66% (according to the pump).  I only had 10 miles until I got home, so I didn't really notice a difference right off the bat.  I don't even know if the computer made any adjustments in that short of a distance (they say 7 miles, but who knows how accurate that is?).  Anyway, then this morning on my way in to work, I could DEFINITELY tell a difference.  I always felt like this motor ran and sounded like shit, that's the whole reason I began this research and stumbled on the E85 topic.  Point being, it runs, idles, accelerates, and even sounds  COMPLETELY different.  I can only imagine this will get better as I drown out the 87 octane with the next tank, and even more so in the summer with some higher ethanol content.  I could care less about the decrease in MPG...I'm sticking with E85, just based on the difference it has made with my tiny 9 mile drive in to work this morning.  Thanks for all the info and tips fellas!

[swathdiver]

18 minutes ago, tim5779 said:

 I don't even know if the computer made any adjustments in that short of a distance (they say 7 miles, but who knows how accurate that is?).  ...I always felt like this motor ran and sounded like shit, that's the whole reason I began this research and stumbled on the E85 topic.  

It ran like crap because of the crap 87 octane.  It would have run much better on 91/93.  It will of course run even better on E85.  We can tell how long it takes to adjust for the new fuel by using our Tech2 or in your case, the MDI/GDS2.  I know a guy who can view his engine functions on his aftermarket navigation display, pretty cool.  Now you'll be looking for excuses to drive it longer, I take my wife out for drives.  

[DONWT15]

6 hours ago, tim5779 said:

So I waited until I was on E, because I wanted to experience the most drastic change as possible.  I filled up last night on the way home from work using E-85 at ethanol content of 66% (according to the pump).  I only had 10 miles until I got home, so I didn't really notice a difference right off the bat.  I don't even know if the computer made any adjustments in that short of a distance (they say 7 miles, but who knows how accurate that is?).  Anyway, then this morning on my way in to work, I could DEFINITELY tell a difference.  I always felt like this motor ran and sounded like shit, that's the whole reason I began this research and stumbled on the E85 topic.  Point being, it runs, idles, accelerates, and even sounds  COMPLETELY different.  I can only imagine this will get better as I drown out the 87 octane with the next tank, and even more so in the summer with some higher ethanol content.  I could care less about the decrease in MPG...I'm sticking with E85, just based on the difference it has made with my tiny 9 mile drive in to work this morning.  Thanks for all the info and tips fellas!

Congrats. Sounds all good. 

[Cowpie]

For me, it is purely economics.  My 2015 2500 6.0 gets about 14 mpg average on regular, which at current pricing in my area comes to about 17.8 cents a mile.  On E85, my 2500 averages about 11 mpg, which at current cost to me is roughly 15.5 cents a mile for a savings of 2 cents a mile.  For even the 6.2L on premium to just break even, at current premium fuel price in my area, it would have to average 21 mpg.  And I find it highly improbable that if there was a 6.2L in my 7000 lb 2500, it is going to average 21 mpg even on a good day.  Maybe on a highway trip, but then, with E85 on a highway trip I can average about 14 mpg.  So the 6.2 would have to average 25 mpg on a highway trip just to break even. Again, highly improbable in a 2500.

 

Just as I did several years ago when we had fuel prices in the stratosphere, my 2013 1500 5.3 lived on E85 for almost 2 years.  Prices are such  that now my 2500 6.0 is living on E85, and will do so as long as the price spreads remain what they are.  I am very fond of flex fuel engines.

[bgbdwlf2500]

On ‎2‎/‎9‎/‎2018 at 12:07 PM, tim5779 said:

So I waited until I was on E, because I wanted to experience the most drastic change as possible.  I filled up last night on the way home from work using E-85 at ethanol content of 66% (according to the pump).  I only had 10 miles until I got home, so I didn't really notice a difference right off the bat.  I don't even know if the computer made any adjustments in that short of a distance (they say 7 miles, but who knows how accurate that is?).  Anyway, then this morning on my way in to work, I could DEFINITELY tell a difference.  I always felt like this motor ran and sounded like shit, that's the whole reason I began this research and stumbled on the E85 topic.  Point being, it runs, idles, accelerates, and even sounds  COMPLETELY different.  I can only imagine this will get better as I drown out the 87 octane with the next tank, and even more so in the summer with some higher ethanol content.  I could care less about the decrease in MPG...I'm sticking with E85, just based on the difference it has made with my tiny 9 mile drive in to work this morning.  Thanks for all the info and tips fellas!

it is a noticeable difference for sure, on mine it stops 1 or 2 injectors from ticking on cold starts as well.

 

So last night I had about 3/4 of a tank and decided I'm going to go back to 87 for awhile but the last time I switched, the computer didn't calculate the alcohol correctly and caused hard starts. I didn't want to fill it with E10 just in case the same thing happened. Before I filled up I plugged in the obd scanner I have and it was reading 80%. Topped off the tank with 87, restarted the truck and hooked the scanner back up. On the way home which was just under 6 miles the alcohol content varied continuously the whole way home from 76, 66, 62, 55, it was just all over the place. This morning it stayed locked in at 67%, I don't know if that means since I shut the truck down that it is no longer calculating again or the 2 fuels have blended and that's where the alcohol % is staying.

[Perseus]

it is a noticeable difference for sure, on mine it stops 1 or 2 injectors from ticking on cold starts as well.
 
So last night I had about 3/4 of a tank and decided I'm going to go back to 87 for awhile but the last time I switched, the computer didn't calculate the alcohol correctly and caused hard starts. I didn't want to fill it with E10 just in case the same thing happened. Before I filled up I plugged in the obd scanner I have and it was reading 80%. Topped off the tank with 87, restarted the truck and hooked the scanner back up. On the way home which was just under 6 miles the alcohol content varied continuously the whole way home from 76, 66, 62, 55, it was just all over the place. This morning it stayed locked in at 67%, I don't know if that means since I shut the truck down that it is no longer calculating again or the 2 fuels have blended and that's where the alcohol % is staying.

What are u using to get the readings

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[bgbdwlf2500]

24 minutes ago, Perseus said:

What are u using to get the readings

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One of the 20 dollar obd scanners bought on Amazon and torque pro from which ever app store you use

[Perseus]

One of the 20 dollar obd scanners bought on Amazon and torque pro from which ever app store you use

Really,I can't seem to get mine to show

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[Grumpy Bear]

On ‎2‎/‎19‎/‎2018 at 6:37 AM, bgbdwlf2500 said:

it is a noticeable difference for sure, on mine it stops 1 or 2 injectors from ticking on cold starts as well.

 

So last night I had about 3/4 of a tank and decided I'm going to go back to 87 for awhile but the last time I switched, the computer didn't calculate the alcohol correctly and caused hard starts. I didn't want to fill it with E10 just in case the same thing happened. Before I filled up I plugged in the obd scanner I have and it was reading 80%. Topped off the tank with 87, restarted the truck and hooked the scanner back up. On the way home which was just under 6 miles the alcohol content varied continuously the whole way home from 76, 66, 62, 55, it was just all over the place. This morning it stayed locked in at 67%, I don't know if that means since I shut the truck down that it is no longer calculating again or the 2 fuels have blended and that's where the alcohol % is staying.

Imagine putting a cup of red dye in 20 gallons of water. It takes awhile to make the entire volume red. (mixing) It takes about 7-10 miles to get a homogenous mix to read at the trucks instrument. Be patient. Turning the truck on and off will not cheat the sensor or make it read in error. 

[bgbdwlf2500]

8 hours ago, Perseus said:

Really,I can't seem to get mine to show

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I'm using the pay version, don't know if you are or not.

[Perseus]

I'm using the pay version, don't know if you are or not.

Yup. It's in the paid version not the free. I upgraded thanks

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[swathdiver]

On 2/19/2018 at 7:37 AM, bgbdwlf2500 said:

So last night I had about 3/4 of a tank and decided I'm going to go back to 87 for awhile but the last time I switched, the computer didn't calculate the alcohol correctly and caused hard starts. I didn't want to fill it with E10 just in case the same thing happened. Before I filled up I plugged in the obd scanner I have and it was reading 80%. Topped off the tank with 87, restarted the truck and hooked the scanner back up. On the way home which was just under 6 miles the alcohol content varied continuously the whole way home from 76, 66, 62, 55, it was just all over the place. This morning it stayed locked in at 67%, I don't know if that means since I shut the truck down that it is no longer calculating again or the 2 fuels have blended and that's where the alcohol % is staying.

 

So how has it been doing since?