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Car_Barn_Bandit
11-19-2012, 10:49 PM
I've been wracking my brain trying to solve my poor gas mileage I've suddenly been getting. Chatted with Murg about a possible hanging Cold Start Injector the other day. Disconnected it and things seemed to get better.

I start off my day in Oklahoma and fill up at a Shell station. Gas mileage has been horrible since. I went nearly a thousand beautiful miles ethanol free. Either Shell is poor quality, has a high ethanol blend or my engine hates ethanol; but I think I've solved the mystery of shoddy MPGs. I found a great app to guide me to ethanol free fueling stations and I'm going to give my experiment a try. Engine is running noticeably smoother on ConocoPhillips. Will update later tonight.

Any have similar experiences with corn fuel?

MrWOT
11-19-2012, 11:05 PM
Heh, try E85. High octane but lower energy content, needs to go about 20% rich or runs like ass. With E10/15 however, I would suspect you just got a lousy batch of gas or they have tank problems. Run a water remover and some lucas, see if it clears up.

METDeath
11-19-2012, 11:09 PM
I've been wracking my brain trying to solve my poor gas mileage I've suddenly been getting. Chatted with Murg about a possible hanging Cold Start Injector the other day. Disconnected it and things seemed to get better.

I start off my day in Oklahoma and fill up at a Shell station. Gas mileage has been horrible since. I went nearly a thousand beautiful miles ethanol free. Either Shell is poor quality, has a high ethanol blend or my engine hates ethanol; but I think I've solved the mystery of shoddy MPGs. I found a great app to guide me to ethanol free fueling stations and I'm going to give my experiment a try. Engine is running noticeably smoother on ConocoPhillips. Will update later tonight.

Any have similar experiences with corn fuel?


Yeah, it blows... E10 sucks gas mileage out of non-knock sensor cars... plus is just in general bad. Fucking corn subsidies.

Murgatroy
11-20-2012, 12:34 AM
High ethanol dropped Chaos down to 18MPG, but we had this conversation.

Car_Barn_Bandit
11-20-2012, 02:31 AM
Ethanol was the culprit. Never really noticed because in Nazifornia it's mandatory for all fueling stations to carry it.

Lonestag
11-20-2012, 03:07 PM
Funny, never noticed any ill effects of Cornahol in my gas.

4thgenceli
11-20-2012, 04:18 PM
I've only had bad experiences with corn fuel. It doesn't agree with my tank. Can't seem to digest it properly.

richee3
11-20-2012, 06:34 PM
I used to be able to jump state lines and get corn-free gas and get 3-4 mpg better. Back to Illinois/Indiana with E10, gas mileage went back down. It never made a huge difference for me but given the choice, I'll take corn-free gas any day.

vip09
11-21-2012, 03:37 AM
Ethanol is for going fast, not economy! I used to run e85 in my Alltrac. It was amazing stuff.

Xander_X
11-22-2012, 05:47 PM
I had 3 injectors go one right after the other in my 91 Legacy Turbo, each time in the middle of a track run. I couldn't figure out why until I thought about how ethenol had just recently been added at the pumps (this was obviously a while ago) .... it's some harsh crap. Damn the man!

BlueDragon
11-22-2012, 08:37 PM
running e-85 in my st-185 for about 3 years now, no issues. Just had the rail and stuff off and all the insulators and seals are in great shape... car is noticeably faster when going from gas to e-85. I think I get about 12-15 mpg though, but it is well worth it for the power. Plus its higher octane so much safer.

Galcobar
11-23-2012, 09:51 AM
Ethanol, particularly at 10-15 per cent, is highly unlikely to cause any damage to components of cars made from 1990 onwards (especially Japanese cars) as their hoses and related components were switched from natural rubber to synthetic formulas which are not affected by ethanol's hydrophilia.

However, ethanol is a very good cleaning agent when it comes to built-up gum, varnish and carbon deposits. It's not surprising for an older car to experience clogs, particularly in the fuel injectors, when exposed to gasoline with an ethanol blend. It's the same danger as faced when running a fuel cleaner such as SeaFoam; large hunks of crud are partially dissolved and thus dislodged, and are now free to shoot down the fuel system to the injector's atomizer.

The mileage issue with E85 is something different. Running E85 in a standard engine is akin to running 95 octane in a 5SFE -- you're wasting the potential of the fuel. An engine designed for ethanol will run at extremely high compression and thus restore the efficiency per litre lost compared to gasoline. Gasoline is high in energy density, but leads to a less efficient combustion design. Ethanol is the reverse, low in energy density but capable of highly efficient combustion.

celica9303
11-26-2012, 04:27 AM
I've never seen over 20-21mpg. In the 7years I've had my Celica ::shrugs::

Car_Barn_Bandit
11-26-2012, 07:51 AM
I do need to disassemble my fuel rails. Engine sounds nice and rough now that I have a fancy exhaust leak. Time for some TLC.

MCcelica
11-26-2012, 08:12 AM
All the stations around me have e-10. I still get the same mileage as the day I bought the car...

Car_Barn_Bandit
11-26-2012, 06:34 PM
All the stations around me have e-10. I still get the same mileage as the day I bought the car...

What brand of fuel are you using?

MCcelica
11-26-2012, 07:27 PM
Conoco.

Car_Barn_Bandit
11-26-2012, 08:18 PM
Conoco is good. Shell is no longer my friend.

MCcelica
11-26-2012, 11:21 PM
I'll help out your testing. Next time I fill up I'll go to Shell and see if my MPG drops too.

Car_Barn_Bandit
11-26-2012, 11:48 PM
I'd appreciate that. I'm going to replace a couple sensors, make some adjustments and clean out the last thing on my fuel system overhaul, the rail.

Under full load (weighted down with all my belongings at about 800lbs) I was getting 18mpg highway cruising at 70mph with 87 octane Shell gas. When I filled up at Conoco/76 ethanol-free I was getting 24mpg at 70mph. My mileage improved a couple more MPGs with 85 octane when it was available. Haven't had a chance yet to see what an empty load will look like, but I will know sometime next week as I have a drive to Kentucky.

MCcelica
01-06-2013, 09:15 AM
I've run 6 tanks through since this thread. Alternating Conoco 91 octane, and Shell E10 91 octane. (1st tank, Conoco, 2nd, Shell, 3rd, Conoco, 4th, Shell etc)
Same driving habits, two different types of tires (Same diameter on the tire though).

I have zero difference in miles per tank. All 6 times, I've gotten to 330 miles when the last light turns off on my gas gauge.

buffalohunter7321
01-13-2013, 05:04 AM
I filled up today with E-85 and could really tell the difference in pick up and go that I liked really well. Now I'll see what the mileage is per tank!? Hope it is better than 230 miles per tank because that is what I was getting on 93 octane.

Nitro_Alltrac
01-13-2013, 09:12 PM
I seriously doubt you're going to see what you were getting with 93 octane. Ethanol has a much better octane rating but contains less energy than gasoline. With the E85 you're going to see worse fuel mileage due to running 85% Ethanol,. On the other hand, with a turbo car, the power will come on well as detonation will seriously decrease.

93celicaconv
01-14-2013, 01:50 PM
On average (winter / summer blends averaged, along with impacts of additives averaged), gasoline produces about 114,000 BTU/gal. E85 fuel produces about 81,800 BTU/gal. It would take about 1.39 gallons of E85 to get the same energy content of 1 gallon of gasoline. Unless you have an engine that, when switching from gasoline to E85 somehow also improves on the combustion efficiency that fuel can offer (most of the times through higher compression pressues), your engine that can burn both fuels will not deliver the compression pressure when on E85 to generate higher combustion efficiency (just an adjustment to fuel volume). So, if you get 30 MPG with regular gasoline, expect to get about 21.6 MPG with E85. If the price of E85 is low enough to provide an economic benefit at this lower miles/gallon value, great! But remember, an engine built to operate on regular gasoline cannot develop the combustion pressure to take advantage of the efficiency or performance benefits E85 has to offer - it doesn't switch this way. An engine built to run on E85 only can be set up with higher combustion pressure, which generates better efficiency and better performance. But such an engine cannot take regular gasoline as a result. It is a world of compromise.

MrWOT
01-15-2013, 12:07 AM
You know, if you aren't octane limited, you'd be surprised at how lean you can go and still make great power ;)

93celicaconv
01-15-2013, 03:04 AM
You know, if you aren't octane limited, you'd be surprised at how lean you can go and still make great power ;)

What exactly do you mean "If you aren't octane limited"? I don't understand the context.

For reference, there is an article from May 2007 about a 2007 Chevy Tahoe FlexFuel vehicle that was driven a round trip for San Diego to Las Vegas and back again, one loop on 87 octane gasoline, the next loop on E85 fuel. All test conditions were exactly the same. At the time, the average gasoline cost was $3.42/gal, the average E85 cost was $3.09/gal. The round trip for each fuel covered 667 miles. The gasoline trip yielded 18.3 MPG at a total gasoline cost of $124.66. The E85 trip yielded 13.5 MPG at a total E85 cost of $154.29. The cost of running E85 fuel on a FlexFuel vehicle was 26.5% more than running this vehicle on gasoline. If you apply today's gasoline and E85 fuel costs per gallon, you can calculate what the results would be based upon the data given here. I really doubt that you will see E85 costing you less to operate than gasoline though.

Car_Barn_Bandit
01-15-2013, 03:19 AM
I'm wondering if this issue is temperature dependent. It warmed up for one day, and I got the same damn CEL codes 25/26.

93celicaconv
01-15-2013, 03:29 AM
The article below is good reading for ethanol enthusiasts. Note the comparison is based upon an engine modification, changing it from running only gasoline to only running E85 (injectors and fuel pumps changed, head modification to increase compression pressures, remapping/tuning the ECU, fuel pressure regulation change, etc.). So don't think a FlexFuel engine can be compared here - it can't as a FlexFuel engine cannot change compression pressures as it senses different levels of ethanol in the blend. But it is a very interesting read.


For years now, scientists have warned of global warming and the harmful effects caused by automotive emissions being pumped into our atmosphere on a daily basis. Combined with an ever-growing urgency to reduce our foreign oil addiction, the government has begun funding corporate America to promote the development and distribution of a cleaner-burning, domestically produced, ethanol-based alternative, known today as E85. Comprised of roughly 85 percent denaturated alcohol-made by fermenting and distilling starch crops such as corn (one acre of which, can be processed into about 330 gallons of combustible ethanol)-high-concentration ethanol fuels like E85 have been slow to catch on stateside. But countries like Sweden and Brazil have been producing ethanol fuels for a number of years from locally grown corn and sugar cane, as an answer to their countries' limited supply of oil.


Now, before you assume ethanol-blended fuel to be exotic, know that your car is probably already burning it; about one-third of all gasoline sold in the United States contains some blend of ethanol, typically up to 10 percent by volume (depending on area), and roadside pumps that offer full E85 sell it, and all its octane benefits, for about the price of premium gasoline.

While the supply and demand of E85 remain low, due to its sparse availability, a handful of automotive enthusiasts hasn't been deterred from exploring its benefits; specifically, that E85 has an octane rating-or the industry standard known as Research Octane Number (RON)-approaching 105; a significant jump from your typical 93-octane premium pump gas, but for about the same price. This higher octane rating allows performance enthusiasts to broaden their tuning capabilities, thus increasing power and reducing the chance of detonation with high compression or boosted applications, with the use of an alternative fuel. And E85 burns cleaner; a cup of standard gasoline set on fire will billow a thick plume of black soot. But a cup of Everclear 190 proof alcohol (95% ethanol and 4.4% water) will burn cleaner, without a trace of black smoke.


The Pros And Cons Of Using E85
Pros
Compared to gasoline, here's a quick overview of what we like about E85:


1 The higher autoignition temperature of Ethanol (689 degrees F, compared to gasoline's 475 degrees F) enables E85 to be more knock-resistant and handle more boost or higher compression.


2 E85 initiates a cooler intake charge, allowing for higher boost pressure.


3 E85 is less volatile than gasoline or low-volume ethanol blends, which results in fewer evaporative emissions. Using E85 also reduces carbon monoxide emissions and provides significant reductions in emissions of many harmful toxins, including benzene, a known human carcinogen.


4 E85's higher resistance to detonation (autoignition) allows tuners to implement more aggressive ignition timing, for improved combustion efficiency.


5 Depending on tuner and engine, a slightly leaner air-fuel ratio (AFR) under partial and wide-open throttle (WOT) can be implemented, helping to increase fuel mileage.


6 The cleaner-burning fuel will minimize residual carbon deposits on intake valves, combustion chambers, and other internal components.


7 At government-subsidized prices, E85 can actually be cheaper to run than gasoline, especially compared to high-octane race gas.



Cons
Converting your vehicle to run on E85 requires commitment and knowledge of proper fuel management tuning. Although the costs of converting a vehicle are relatively low, we found some issues that came up with using E85.


1 At 9.76:1, E85 has a different stoichiometric AFR than gasoline (14.7:1), and requires fuel/timing maps be converted to compensate. We won't go into details with Lambda or stoichiometric values but make sure your tuner is well aware of these changes.


2 E85 requires the use of 40 to 50 percent larger fuel injectors, to compensate for its 40-45 percent increase in fuel demand. The change in stoichiometric AFR from 14.7:1 with gasoline to 9.76:1 with E85 is 66 percent, but the resulting flow needed is only 40 percent greater, due to E85's higher density than gasoline; your vehicle's check engine light (CEL) may flash a "lean condition" code, resultant of this.


3 An aftermarket fuel management system will expand the parameters needed to tune the vehicle to accept the new E85 purging through its system. The car will not run properly on E85 with a factory ECU.


4 Cold starts can become an issue for those who use E85. As we experienced with our test EVO, it took more than a minute to finally get the engine to crank over. This can be a problem for those who live in colder climate areas, but in sunny California, we don't see this as a major concern. To remedy this problem, you can increase the percentage of standard gasoline used in mixture with E85 to initiate cold starts.


5 Since cars running E85 require more fuel, a tank of E85 will not run as far as a tank of gasoline, and more frequent refueling will be needed. Properly tuned, E85-burning cars will range only 80 percent as far as those burning conventional gasoline.


6 Playing with ethanol-to-gasoline mixtures or periodically switching from gasoline to E85 requires changes in fuel pressures. Switching over isn't a simple run-to-the-pump-and-fill scenario


7 Although E85 is not a corrosive material, ethanol has been known to damage certain rubber, seals, and internal engine components. Most vehicles produced prior to 1987 are not compatible with the chemical composition of E85, and some retrofitting of fuel lines, pumps, and vacuum hose may be needed, depending on vehicle.


Converting a vehicle to run E85 could be done in a day's time, by simply draining fuel, changing injectors and tuning. Bigger injectors, a good fuel pump, and E85 are nearly all that is needed. Everything else can be done in the ECU. Shawn Church, owner of Church Automotive and tuner of our E85-powered EVO VIII test vehicle, prefers to tune E85 with a good standalone engine management system, like the AEM EMS. "I'd say that if you have a regular source for E85 available, it's a hell of a good deal; cheaper than gas-especially race gas-and excellent performance. And the owner of this EVO VIII is averaging 16-17 mpg in the city on E85, so the drop-off in economy isn't that noticeable."

buffalohunter7321
01-15-2013, 03:54 AM
I have about 20 miles on the tank full so far. And will let every one know how far this E85 will take me.
On the 93 octane I was only getting 215 to 225 miles per tank full, that only comes out to around 12/15 miles per gal.. My car as no cat just a straight 3" down pipe and that is it. No exhaust from there back. So running with out the Cat. really cuts down on gas mileage!
To run this tank out will take me about 1 1/2 weeks. I just drive it around town mostly. I'll post the results when that happens.

MrWOT
01-15-2013, 05:56 AM
What exactly do you mean "If you aren't octane limited"? I don't understand the context.

For reference, there is an article from May 2007 about a 2007 Chevy Tahoe FlexFuel vehicle that was driven a round trip for San Diego to Las Vegas and back again, one loop on 87 octane gasoline, the next loop on E85 fuel. All test conditions were exactly the same. At the time, the average gasoline cost was $3.42/gal, the average E85 cost was $3.09/gal. The round trip for each fuel covered 667 miles. The gasoline trip yielded 18.3 MPG at a total gasoline cost of $124.66. The E85 trip yielded 13.5 MPG at a total E85 cost of $154.29. The cost of running E85 fuel on a FlexFuel vehicle was 26.5% more than running this vehicle on gasoline. If you apply today's gasoline and E85 fuel costs per gallon, you can calculate what the results would be based upon the data given here. I really doubt that you will see E85 costing you less to operate than gasoline though.

The test is skewed, because you aren't taking advantage of the fuel.

I look at how much power can be made per volume of fuel.

If you want a real test, use a turbocharged car, and tune to leanest safe power with both, then check the difference between them ;)

edit: Just FYI, my GS sits dormant at the moment because I'm having the PCM retuned (shipping back and forth to Canada takes a long damn time :sadcry:) It will come back tuned far leaner than it was, dangerously lean on just 91 octane. But I mix my own blend of additives, and I'm anticipating a fairly decent gain in power AND mileage.

Galcobar
01-16-2013, 09:46 AM
What exactly do you mean "If you aren't octane limited"? I don't understand the context.

For reference, there is an article from May 2007 about a 2007 Chevy Tahoe FlexFuel vehicle that was driven a round trip for San Diego to Las Vegas and back again, one loop on 87 octane gasoline, the next loop on E85 fuel. All test conditions were exactly the same. At the time, the average gasoline cost was $3.42/gal, the average E85 cost was $3.09/gal. The round trip for each fuel covered 667 miles. The gasoline trip yielded 18.3 MPG at a total gasoline cost of $124.66. The E85 trip yielded 13.5 MPG at a total E85 cost of $154.29. The cost of running E85 fuel on a FlexFuel vehicle was 26.5% more than running this vehicle on gasoline. If you apply today's gasoline and E85 fuel costs per gallon, you can calculate what the results would be based upon the data given here. I really doubt that you will see E85 costing you less to operate than gasoline though.

A flex-fuel vehicle is a gasoline-powered vehicle which has the option of running on E85.

It's a great tool for the car manufacturers, who get credit for producing low-pollution vehicles while knowing that the vast majority will run on standard gasoline.

However, it's not optimal use of the E85, which is a very different fuel than gasoline. Running it through the same engine will not produce the kind of efficiency in either fuel consumption or power production that a purpose-built engine.

93celicaconv
01-16-2013, 01:53 PM
A flex-fuel vehicle is a gasoline-powered vehicle which has the option of running on E85.

It's a great tool for the car manufacturers, who get credit for producing low-pollution vehicles while knowing that the vast majority will run on standard gasoline.

However, it's not optimal use of the E85, which is a very different fuel than gasoline. Running it through the same engine will not produce the kind of efficiency in either fuel consumption or power production that a purpose-built engine.

Galcobar, you couldn't have stated this any better or clearer - you are spot on.

Just like an engine built to run on either gasoline or diesel/kerosene. Can it be built - YES (in fact, my dad had a tractor built in the 1930's that had this combo fuel engine on it). Is it optimized for both fuels - ABSOLUTELY NO. It will always be a compromise. Diesel engines work in this country as a purpose-built exclusive fuel engine because there is widespread distribution of fuel outlets throughout the country, just like gasoline. E85, on the other hand, does not exist in all areas of the country (can't find it on the east coast, the southern sun-belt, or the west coast). So how will the owner of a purpose-built engine that can only run E85 travel to these locations? What will the owner do when the tank is empty? Hence the problem with E85 fuel & purpose-built engines to take full advantage of this fuel's properties - it will be very limited to commuter use unless where the owner knows where to get E85 fuel. In a way, too bad. But getting an infrastructure set up nationwide to allow purpose-built engines optimized for E85 would be something we may never see.