LT1_E85_Corvette

For some reason alot of old timers, and people lacking general knowledge about fuel consumption seem to think this. E85 is not allowed in most engines because of lack of computing compensation. Every single car has the ability to run on E85 suggesting it has been tuned properly. My LS3 has been running on it for nearly a year and a half, with zero fuel mods or issues. I have logged almost 18,000 miles!

Raitzi

I agree. Ethanol producer in my country uses waste food and sawdust.(we only have one oil company making and selling e85)

Latest finding is flexifuel cars in winter here show that it does not suit to winter use. Even Ford representatives said that they do not recommend using it in winter in their flexifuel cars.(they do not start/run well)

Hemi Dave

I have a couple of gas stations who have been selling E85 for years where I am.....and it sells too. Guess I am lucky.

SCM_Crash

There's an E85 station near my office.

If the C7 turns out to make lots more power with E85, regardless of the economy, I'll be running it.

If E85 makes exactly the same power as E10, and gets nearly the same economy too (which is actually possible now), I will still run it.

If E85 smells better out of the tail pipes than E10, I'll run it.

If the engine sounds better (which from what I've heard, E85 running engines sound different), I'll run it.

If E85 is a little cheaper than E10 and offsets the economy drop, I'll run it.

If E85 is better for the environment, I'll run it.

speedlink

I'm thinking this thread will become a little contentious.

I agree with you 100%. Not only with your observations, but gets much less fuel economy. Very bad idea. Thanks government.

SCM_Crash

On vehicles that are specifically built for E85, this isn't the case.

Just saying...

Larry/car

Corn is a terrible food source. When you eat corn very little nourishment is received. It fills the stomach but doesn't digest. Might as well make fuel out of it.

SCM_Crash

I personally don't like Corn.

Make fuel out of it!

Although, I'd like to see what kind of fuel can be made from bamboo.

JoesC5

Big *** GM SUV with FlexFuel was tested in a real world situation. They ran a tankful of pure gas through the vehicle and then ran the route, EXACTLY, but this time with E85. The SUV got 27% worse gas mileage running the E85 vs the pure gasoline.

JoesC5

I love homemade cornbread. It just doesn't taste the same when made from Mobil1 10w30 instead of corn meal. I also eat a lot of poultry. I believe corn is one of the feed stocks for them, not EXXON 91 octane gasoline made from crude oil. Some of the items I eat contain eggs. The eggs come from chickens that are not fed Phillips 66 gasoline. Sometimes I like a ham sandwich or a BTL. They taste better if the hogs are fed corn then motor oil.

Zymurgy

Most corn is fed to livestock. Extensive use of corn for ethanol has rasied the cost of animal feed. Brazil produces ethanol from sugar cane.

SCM_Crash

I saw that test. It was anything but a scientifically accurate test.

But lets ignore that since it's completely invalidated by my second point:

While that vehicle was designed to accept E85, it was not designed to RUN E85. Meaning, it wasn't designed specifically for E85. A car designed specifically for E85 won't be able to run E10 safely unless it's both direct inject and able to change compression and spark advance dynamically.

An E85 specific engine will require a LOT more timing and compression. If you advance the timing and bring up the compression to 13:1 or higher, you begin to see the advantages of E85. Because you'd make MORE power with E85, you'd want to change the gearing for E85 vehicles too so that you're at a lower over-all RPM.

The more power you make efficiently, the better your economy will be. Meaning, even if you need X amount of fuel to reach Y RPM, you may not need to reach Y RPM to begin with if Z HP is greater than necessary for maintaining speed at lower RPM.

I hope that makes sense.

JoesC5

What automobile company makes a car that runs only on E85?

SCM_Crash

None... But if you read my post, you'd note that the items to make an engine use E85 effectively are things that the GM SUV didn't have but the C7 LT1 does.

Hint hint...

JoesC5

Hint Hint. The LT1 has 11.5:1 compression, so that it can also run on 87 octane E10, not 13:1 or higher CR.

Just like a pure electrical car(ie: Leaf), a car designed to run solely on E85 is not practical in the real world.

Oh, and the SUV FlexFuel test was a valid test, as it represented the conditions that the SUV sees in everyday driving by everyday drivers. Real people don't drive their cars in laboratories. They get in their cars, drive them in traffic, drive them on the expressway, drive them when it's -15 degrees and when it's 115 degrees. This is what the Federal government has to say on the subject. " However, since ethanol contains less energy per volume than gasoline, FFVs typically get about 25-30% fewer miles per gallon when fueled with E85." http://www.fueleconomy.gov/feg/flextech.shtml Kind of contradicts what you had to say, doesn't it? ..."I saw that test. It was anything but a scientifically accurate test."





Ever read the EPA window sticker on a new car? Ever wonder why people don't get exactly the gas mileage shown in the BIG numbers on that window sticker? Ever wonder why the small print on the window sticker gives a broad gas mileage range? A 2009 C6 Z06 has BIG numbers that say city MPH 15 and highway MPG 24. The small print says expected range for most drivers 12 to 18 MPG city and expected range for most drivers 19 to 29 MPG highway. It's because real would driving is different then laboratory driving. Real world driving of a 2009 Z06 ranges from 12 to 19 MPG city and ranges from 19 to 29 MPG highway, not exactly 15 MPG city and 24 MPG highway that is found in laboratory testing.

Wonder why there are so few retailers selling E85? It's because in real world driving, people with FlexFuel vehicles found out that they got 27% worse gas mileage when they filled the tank with E85 instead of E10 or pure gasoline. Even in my Z06, which is not a FlexFuel vehicle, I get 1.5-2 MPG better gas mileage when I run pure gasoline then when I run E10. THAT IS real world results.

SBC_and_a_stick

Sadly, it is fed to livestock even when it shouldn't. There is corn in almost everything we eat in U.S. many under the form of corn syrup. It is disgusting.

I'd rather sweeten my coffee with true sugar cane and throw the corn in the fuel tank.

We should feed cows grass and cars corn. Makes way more sense to me.

johnglenntwo

JustinStrife

The world suffering from lack of food, isn't my, or America's problem. We produce enough food for ourselves.

And if I tuned my car for E85, you're damn right it would make more power than the sewer water 91 octane that we get here in California. Boosted cars, and high compression cars, LOVE E85 if tune properly.

NSC5

Just like the 3.6 used in the CTS, ATS, and other applications. This engine has a 11.5:1 compression ratio and the recommended fuel is regular (87 octane).

The non-DI version of the 3.6L has a 10.2:1 compression ratio but 89 was recommended in it for best performance. It seems a major advantage of DI is the ability to increase the compression ratio without requiring higher octane.

It will be interesting to see the fuel recommendations for the LT1 but I wouldn't be surprised if 87 is considered acceptable.

SCM_Crash

I guess you don't know much about the scientific method.

If they wanted to do real tests on this, they would have used two identical vehicles and performed the tests on both vehicles at exactly the same time, side by side, but one in reverse order of which fuel was used and compared the results against each other using one-another as a "control". AND they would have had to do this for each fuel more than just once. To get consistent results, they'd have to perform this test a hand full of times. Then they'd have to compare the drops in performance and economy by cross checking the difference (in %) of performance between the two vehicles themselves on each test.

But that's OK. That test fails due to the fact that they performed the tests at different times under different weather conditions (admitted by the testers).

Real world tests aren't done on one car at a time. GM didn't send just one Corvette mule out for testing in different conditions. REAL engineers and scientists do things right. That video supposedly showing a drop in economy and performance was as scientific as a high-school science project. And I'd grade that closer to a C-.

ANYWAY, back to the valid points:

While the LT1 is 11.5:1, it has variable valve timing, allowing it to increase compression by allowing more fuel/air into the chamber before the compression stroke, and can in fact continue to add fuel once the intake valve is shut before and during the compression stroke because it's direct injection. It may not make it to 12:1, but still higher than the compression you'd find in the SUV they tested, which has a compression ratio of 9.2:1. That's an ENORMOUS difference in compression.

Secondly it wouldn't matter if the tests are done in a lab or on the streets. If the stop/go timing is the same, the fuel usage is relative. By testing in a lab, the environmental variables can be controlled to yield results that can be taken seriously.

For example, I've taken my 2003 Z06 to Vegas at least 6 times from Los Angeles. In every single drive to Vegas and back, I averaged a different number. Well, I'm filling up at the same gas station (a Chevron by my house) with 91 octane and I'm going approximately the same distance on the same route each and every time. Sometimes I averaged as low as 25MPG and sometimes I averaged higher than 29MPG. In any case, the variables were almost certainly the weather, traffic and the time of day I left. (In the video they admit that traffic is also another variable that changed.) And if you think the weather doesn't change much from day to day, you're wrong. I went to Vegas on New Years Eve and went back on New Years day. TOTALLY different averages. And the weather was different too. It started snowing in Vegas.

BUT... Moving on here. That truck also didn't have direct injection. The LT1 does. Because of this, the LT1 can handle 87 octane; not because of the "seemingly low compression". Direct injection allows the fuel to be added later than standard injection because the fuel doesn't run through the intake valve. That means that pre-detonation isn't as much a factor here. On non-direct injection motors, the fuel is mixed with the air and run through the intake valve. That means that the fuel must be in the chamber before compression. With high compression, the hot carbon residue on the pistons can pre-ignite the fuel as it's compressed causing the pre-detonation associated with low octane fuel and high compression. That's why NONE of the low-octane non-direct-injection cars had high compression. What kind of fuel do you put in a GM SUV? 87. What kind of fuel have you traditionally put in modern Corvettes? 91+. Why? Because they're higher compression than the truck motors. That's also the reason stock truck motors are often times used for forced induction builds. The heads are already lower compression.

Now if you're going to tell me that there's no difference between E85 running on a motor that has a 9.2:1 compression ratio is no different than running on a motor that is 11.5:1, then you're either in denial or highly uneducated about how this all works. You pick.

And of course, that motor in the Tahoe they tested doesn't have variable valve timing. The later models did. Too bad they didn't test with the later models. I believe the test was with a 2007 Tahoe. The 4.8L V8 FF Tahoe had the worst possible compression you can have for flex fuel. Period. It's quite unflattering and there's absolutely no way that the truck could have used any of the fuel's advantages. Instead, GM's Flex Fuel systems were just a fuel map. And that fuel map only increased fuel 25%. There was no advancing of timing or anything. JUST fuel additions.

That being said, WHY (oh WHY) would you think that a FFV that has no real mechanically dynamic controls could use E85 efficiently? Just because it's a FFV doesn't mean it can use that fuel efficient. It just means that the injectors and fuel map are setup to use it as a type of fuel. It does NOT mean it's capable of using the fuel to its advantages.

The LT1 will be capable of doing this for the most part. While it won't be able to increase compression up to 13-14:1, it will be able to take advantage of spark and valve timing as well and fuel injection timing (which is key to building higher compression without forced induction).

Which brings me to my last point, the forced induction LT4 will likely see MASSIVE gains with E85. And since the LT1 and LT4 motors will likely be identical other than intakes, it's likely that the LT1's ECU is ready to make good use of the E85 fuel more than any other GM vehicle ever.