School me on E85, Flex Fuel - Page 3

TheGerman · 10-09-2018, 12:30 AM

There are two properties that are important when it comes to E85. First, it has a much higher octane rating at 105 octane which is race gas territory. That's the reason why, as described above, some purpose built performance engines are tuned for E85. The other property is that E85 has only about 75% of the energy density of regular gasoline. That's why the mpg goes down.

The fuel system in an E85 vehicle needs to be able to deliver more fuel into the cylinders to make up for the lower energy density. Some manufacturers also tweak the engine controller to take advantage of the higher octane rating. In the case of GM, GM claims 25hp and 33 ft/lbs for the 5.3l truck engine. Don't know about Ford, and I'm fairly certain RAM does not have better ratings with E85.

KnP · 10-09-2018, 07:23 AM

E85 is a better fuel even that has Less BTUs but Higher Octanes. There is a misunderstanding about Octanes and BTUs. Octane is not a measurement of Power, is a measurement on how Gasoline is tolerant to autoignition under pressure. Lower the number, the more volatile. The fuel need to burn, not to explode.

Now, why E85 even that is cheaper, with higher octanes gives you crappy mileage? Some is not right....

Is the engine (also, Fuel/Air mixture, 14.7:1 air to fuel for gasoline, about 21:1 for E85)

To make a Flex Fuel Engine, you have to fabricate it to use all sorts of octane ratings. The lowest one is at about 87. The compression ratio and fuel/ignition management is set to run with that octane rating as the lowest. When you pump E85 the advantage of using a higher compression is lost, is the same thing as using High Octane fuel on a Low Compression Engine. You can put 180 Octanes on a 8:1 compression ratio engine and you might get 5% gains and is due to Ignition Timing advance. All Gasolines, Low to High Octanes have the same amount of BTUs.

Computers made this possible, they can adjust Air/Fuel Mix and Valve/Ignition Timing quicker.

Why then, raise the compresion to accomodate E85 and extract the most out of it? There are no Variable Compression Engines. Nissan is working on one and is pretty darn complicated. Is not as easy as Variable Valve Timing.

If the mfg build the engine with a 15:1 Compression Ratio to get the besr out of E85, the engine is locked down to E85 only, no longer will be a Flex Fuel engine. Any other Gasoline will predetonate, will self ignite like a Diesel Engine.

I know some people that made a LS2 GM engine to run E85 only. Runs pretty darn good, plenty power, cleaner burning and great fuel economy.... however, they can only run 1 fuel and is E85, AVGAS or Racing Fuel

If you have some sort of Forced Induction, then, E85 is your best friend.

sunnman · 10-09-2018, 07:51 AM

Everything I have read says pretty much the same: less per gallon but because of less power you end up spending more. I asked my mechanic about it, he said even though today’s flex fuel engines say it’s ok, engines still have issues from running it. He recommends to never use it.

spock123 · 10-09-2018, 09:31 AM

I just saw where the government was going to E85. It looks like if the government wanted to use more ethanol it would import cheap sugar to use instead of corn, just my opinion which isn’t much

KnP · 10-09-2018, 09:54 AM

At this point, I rather have GMO Corn for Fuel than for Food. Beside, Corn is not really food, is more of a filler with next to none nutritional value. Also, High Fructose Corn Syrup is a harmful sweetner that should be banned.

So yes, Corn for Fuel... sure.

A32Deuce · 10-09-2018, 10:01 AM

Feed for live stock!

babock · 10-09-2018, 10:57 AM

The big problem with corn for fuel is that so much fertilizer is used, the fertilizer runoff into the rivers and then eventually into the gulf is becoming an issue.

KnP · 10-09-2018, 11:20 AM

Instead of growing so much Corn, scale it back down and grow some more useful. However, by Fischer–Tropsch process, is possible to convert, plentiful Natural Gas to Ethanol. Is a proven process that works, in WW2 the Germans made Liquid Synthetic Oils and Fuels from Coal and Natural Gas.

Well, we are deviating from the topic but I will say one more thing. The Gov subsidize farmers to grow more Corn. Take the Gov intervention and they will grow some the market will buy or need. Demand creates opportunity.

Is interesting and makes you wonder... when the Gov gets involved, everything goes to hell.

babock · 10-09-2018, 11:26 AM

The ethanol being added was initially an emission thing since we needed oxygenated fuels. With direct injection engines becoming the norm, this will eventually not really be needed since the advantage of oxygenated fuels will be greatly diminished with direct injection. Now it's a "where is our fuel coming from" issue.

47driver · 10-09-2018, 11:32 AM

Midwesterner raised in a farm family, still with 2700 acres in South Dakota...

At first the corn ethanol looked good to us. Government money raining from the sky. Then we realized feed corn prices were going to go through the roof. When you raise cattle, that is important. The ethanol (from sugars-or starch for those purists) that comes from corn is some of the most expensive ethanol known to man. Once the government removes itself from the equation, it won't be profitable for anyone.

I won't burn it, and no one in my family will sell corn to the ethanol industry.

KnP · 10-09-2018, 11:48 AM

What I was told....

Platinum and Palladium that is in the Cathalitic Converters will stop reacting when they come in contact with Lead. An Octane booster used for decades was Tetraethillead. The Unleaded Gasoline was born when this antiknock additive was removed. They started to blend with Ethanol because it has a Higher Octane number. So is a number averageing game. Pure Raw Stock Gasoline has very low Octanes, some around 60. Now mix these 2 together and is possible to bring the Octane Rating to around 90.

Back in the 70s, the only viable alternative was to lower the compression ratios. Cars pre 72 had a hard time running Unleaded Gasolines on 12:1 compressions, so there you have the choice of Leaded and Unleaded. Also, in order for the Cat to work, the fuel air mix has to run a bit richer, also, in California Models, an Air Pump was added to help the Cat (talk about a worthless afterburner). Another kiss of death are the NOx created at high temp and pressure in the combustion chamber.

It tickles me to see the "Unleaded" sign when all street gasolines are unleaded (beside AVGAS 100-110 LL and other fuels).

Now as far what is more suitable as fuel I say Ethanol is my prefered choice. Why, is cleaner, can be produce from all sorts of sources on many different processes and is biodegradable. Gasoline got the upper hand because was a Solvent sold at drug stores, very cheap and was a waste byproduct. Oil Companies, instead of dumping it in rivers, burn it, they saw a great business opportunity to dispose they waste at a profit.

MCTroy · 10-09-2018, 08:17 PM

Anyone have long term results with ethanol? I have been told it burns hotter and therefore rings. Valves and gaskers will not last as long.

babock · 10-09-2018, 08:48 PM

Quote:

Originally Posted by MCTroy

Anyone have long term results with ethanol? I have been told it burns hotter and therefore rings. Valves and gaskers will not last as long.

Probably happens where an engine doesn't adjust the fuel mixture properly so it's running lean. Ethanol actually should burn at a lower temp since it has lower BTUs than gasoline.

KnP · 10-09-2018, 08:51 PM

Want to know a bit more of Ethanol/E85 build engines, follow this guy in Australia. He is a Winemaker with his own Vineyard. Modified his Holden Comodore Station Wagon with a L88 to run on E85. The man is a genious, he goes through a lot of details. Also had the assistance of V8 Supercar (Aussie NASCAR) series engineers. He is the one behind the Pirate Cru wine in South Australia.

I learned a lot from this guy.

https://forums.justcommodores.com.au.../#post-2900251

BTW, for the unawared... Holden is GM Australia. They are the ones that engineered and built the Pontiac GTO (last version) aka Monaro, Pontiac G8, Caprice PPV and the SS aka Commodore VE and VF. These guys know how to build an Euro handling with American Muscle car. I am glad that I own one with the L76, so much potential on these cars.

tomingram · 10-10-2018, 04:34 PM

Quote:

Originally Posted by ADVtraveller

I have a 2017 Ford F250 6.2 gasoline. It's got the Flex Fuel badge and I'm considering trying E85 for my next full up.
I pull a 10,000 lb fully loaded, FR bumper pull toy hauler.
Anyone comments from folks with real world experience using the ethanol - E85 in their tow vehicle, would be appreciated. Pro and Cons.
Internet searches say it's more power but less mpg.
Real world comments?

Thanks

On my fx4- f150 I loose 1,mpg according to ford ,you need to run more then on tank of E85 for the computer to adjust to fuel.It does burn hotter,,,it may show on your heat gage.all & all I did have more power.

tomingram · 10-10-2018, 04:37 PM

[QUOTE=tomingram;1947325]On my fx4- f150 I loose 1,mpg according to ford ,you need to run more then one tank of E85 for the computer to adjust to fuel.It does burn hotter,,,it may show on your heat gage.all & all I did have more power.

cmysstailights · 10-10-2018, 04:37 PM

Quote:

Originally Posted by tomingram

On my fx4- f150 I loose 1,mpg according to ford ,you need to run more then on tank of E85 for the computer to adjust to fuel.It does burn hotter,,,it may show on your heat gage.all & all I did have more power.

You have to go threw atleast 1 tank change, engine will run cooler not hotter with ethenol. I have had no issues running e85 in all 3 of my vehicles.

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