E88 fuel

[SuperDuper]

As the title suggests, was curious if anyone has ran or is running E88 fuel in these newer 6.6 engines?  With the prices of gas soaring was curious if it would be worth the few cents a gallon savings. 

[MTU Alum]

I assume you mean E85.  E85 is an option that is only available on work trucks starting in 2021.  You get about 20% less fuel economy in my driving.  I usually get about 13.5 mpg on E10 in combined driving and around 11 mpg on E85 in combined driving.

 

#iworkforGM

[CamGTP]

Saying E88 is likely the wrong way to say it if I think I know what he's getting at. Here in the midwest we sell 88 octane fuel that is up to 15% ethanol and in many cities it's up to 30-40 cents cheaper per gallon than regular 87 octane. Though some stations will only sell it 5 cents cheaper just because they want to rake in profits on that fuel.

 

You'd be just fine running 88 octane, I know of lots of people that do it and there is really no big difference in fuel mileage compared to the E10 87 octane fuel.

[shakenfake]

Yeah around here E88 is only 5 cents cheaper. I saw like a 3 MPG loss in my girlfriend's 2017 Corolla. If it was 30-40 cents cheaper that would be worth it but not 5

[newdude]

On 3/21/2022 at 11:50 AM, SuperDuper said:

As the title suggests, was curious if anyone has ran or is running E88 fuel in these newer 6.6 engines?  With the prices of gas soaring was curious if it would be worth the few cents a gallon savings. 

 

 

You can run it if its flex fuel equipped.  The only trim that flex fuel capability is an option on is the WT trim on Chevy.  Any other trim or a GMC, can't run it.  

[SuperDuper]

CamGTP, you are correct. I was referring to 88 octane. I’ve seen it listed as E88. Thanks for your response. I’ve seen it all across the board as far as how much cheaper it is compared to 87 octane. I’ve been tempted a few times to fill up on it, but wasn’t sure the impact it would have, if any. 

[Kjduvall]

16 hours ago, newdude said:

 

 

You can run it if its flex fuel equipped.  The only trim that flex fuel capability is an option on is the WT trim on Chevy.  Any other trim or a GMC, can't run it.  

On a optioned up 2021 GMC w/t I got it when it was ordered. But on to e85 talk, you guys who run it gas mileage aside do you notice much power increase ( seat of pants any way). Haven't put any in mine since purchase, just curious as I have easy access to it and a company fuel card, so mpg or fuel cost is not in my equation.

Edited March 23, 2022 by Kjduvall

[CamGTP]

Saying you can't run E15 88 octane is only because that's what the book says.

 

That's like saying E10 fuel is always 10% ethanol, which is rarely ever is. I get 88 octane all the time and the ethanol content varies alot between 12 and 15%, so it's pretty much zero difference than E10 fuel. For even more information the trucks that are not flex fuel have a pre-programmed stoich ratio of 14.1 to account for E10 fuels. So if it's only got 7-8% in that batch of fuel the stoich is now wrong the computer will trim fuel out with the o2 sensors and if you put fuel with 13% in, the computer again will account for that and be just fine. It's well within the computers working range.

 

I have a 5.3 and the E85 power ratings published for the 2014 model year gave the trucks like a 28hp increase with E85 I think and similar torque. The power increase can be felt a little bit but it's not a huge amount with all stock tuning. It can be noticed a little more when towing because E85 will basically never spark knock and pull power away under heavy load. There is a much greater hit to fuel mileage while towing on E85 but that is a given.

 

My unloaded fuel mileage on regular 87 compared to 88 octane is pretty much the same. Can still get over 20mpg on long highway trips and city mileage maybe 1 mpg less.

[Grumpy Bear]

Sometimes called UNL88 or more recently E-15 but never E88. Alcohol content will test at 14% thanks to the ATF; Ethanol sold for fuel blending is 'denatured' 1% by law with petroleum distillates. 

 

E-85 is the ONLY blend that allows a 'range' of alcohol content. 51% winter to 83% summer at the pump. 85% canned race fuels Local pump stuff is more often than not around 72-77%. 

 

All others will be 1% below their E value. Yes there are current attempts to allow 'ranges' for other fuel but not yet law.  

 

It, 15% blends, will not harm any licensable motor vehicle sold in the USA starting with the 2001 model year. By LAW. 

 

Economy losses are straight up chemistry. Carbon/oxygen balance equations. 

 

Initially cost of E-85 was based on this graph below as compared to unleaded alcohol free 87 octane fuels thus to make $$$$ sense it's price had to be about 26% less than 87 E-10. More recently the fuel companies have taken advantage of the fuel subsidies and consumer ignorance (in a growing number of markets) and have been pricing at some percentage below the price of high octane equivalents, that is E10 91-94 octane, based on the actual test percent. and pocketing the price difference. This also negates the reason the government agreed to the deal. 

 

So now we subsidize when we pay our taxes and again to the unchecked tax of  corporate greed and willful consumer ignorance. 

 

 

 

In Illinois I have never been able to make E-85 at any test percent cost effective or even break even. My truck runs just fine on 87 E-10. 

 

Would UL 88 be cost effective? It would have to be priced 2% below E-10 87 to be a wash. Some marginal cleanliness to the oil side of the motor might make 1% more a good trade. 

 

Anyway, my 2 cents on the topic.

You all have a nice day

 

 

I'll let you get to the anecdotal arguments than the graph is hog wash. 

 

Edited March 24, 2022 by Grumpy Bear
spelling

[customboss]

SUPERDUPER ; 

 

Ethanol is ideally optimized in an engine that uses mechanical energy as a prime driver.

 

Since the US and most of the world "chose"  heat energy focused fuels like gasoline sadly even our flex fueled engines are nothing but heat energy engines with MIL parameters opened up a bit.  

 

Grumpy Bear and CAMGTP are  correct,  finding a sweet spot for the octane boost and an engine that can advantage the mechanical energy gain of a certain % of ethanol.   

 

I just drove back from DFW metro mess and tried Race Trac  E15 and for an interval and it did very well in my 2022 LTD Trail Boss L3B turbo 4. 

 

Super Duper, from what little I know about the 6.6L V8 I would guess that up to 20% ethanol in a well tuned engine would benefit the user in lower cost and nearly the same MPG.  

 

Grumpy is right, ethanol burns cleaner and removes carbon and is less stress because of that on the engine oil.   It just doesn't have the same BTU per unit of gasoline. 

 

Ethanol is anhydrous so on our closed fuel systems water is NOT a player like it would be in a open vented fuel system. 

 

I have tested E85 to E100 for years with great results especially in Turbo 4 cylinders that can be optimized the clean fuel.   

 

Stopping carbon deposits in DI engines using higher doses of Ethanol might counter the MPG drop over time from that effect. 

 

 

 

 

 

 

 

 

 

 

[Black02Silverado]

My daughter has used E15 or 88 octane fuel in her 2012 Cruze for over 60k miles now.  No issues at all. No hit on economy either.  Her Cruze isn't a flex fuel vehicle either. 

 

To me I would rather have the benefits of a cleaner burn and higher octane than anything.  This is why I mix E85 at a 50/50 mix in most of my non flex fuel vehicles.  I converted our Suburban over to FF and had Black Bear Performance tune it accordingly.  Kind of pissed that GM stopped it as an option.  Not like they didn't already have all the parts to continue on their vehicles.  Give us, the consumer the option to use it or not.

 

Unfortunately since we moved E85 isn't as available as it was so it isn't get used as much.  But when we are anywhere it is available I fill up. 

 

Circle K stations are popping up here like Starbucks and they are smart and have all these available at every pump so no more waiting for anyone getting gas to move when I need to fill my diesel. Also the non ethanol is great for lawn equipment and boats, since we are on the coast.

 

[Davew277]

FWIW, I try to only use ethanol-free gas.

When I was frequently travelling between Washington and Florida I would normally just buy E10 because I didn't want to hunt around for ethanol-free. But I noticed that I got more MPG from gasoline purchased within a few hundred miles of Kansas City. Like 4-5 mpg better (I was in a 5.7L Hemi Jeep Grand Cherokee, FYI). It's funny because the gas in that area is also some of the cheapest in the country... YMMV.

Edited December 16, 2022 by Davew277