Zero ethanol gas fuel economy

[bruceb58]

Consumer reports got almost the exact same numbers
http://www.consumerreports.org/cro/2...bate/index.htm

I would seriously hate dropping 25% of my range. When I tow my boat to Lake Tahoe, I can get there with one stop.

 

[thumpar]

In my state it is "up to 10%". I have not seen any E85 stations. In the 2 boats I have only run regular pump gas. There are a couple stations that sell E0 but they are only on the Premium fuel or at a dock and cost around $1+ more. I can see maybe worrying about it in a car depending on the price differences but in a boat the last expense you worry about it fuel price difference. They all drink like crazy.

 

[airshot]

You apparently don't understand how flex fuel vehicles (GM in my case) are set up. First, the engine management system knows what type of fuel is being burned through a sensor in the tank. It is also smart enough to know what the rough mix is. Second, knowing what the fuel type and mix is, the engine management system along with the knock sensors can advance engine timing to take advantage of the higher octane in E10 - E85 so as the "tuners" indicate, performance is better. So much for the crappy running -- that is simply not true. Injector pulse width is also adjusted since more fuel is required which accounts for the slightly lower fuel economy. Many on this forum have seen my posts on this topic and this one is rather timely since I just returned from a 2100 mile, 13 day road trip to Iowa, Nebraska, Wyoming, Colorado, and South Dakota. Residents of several of those states know the speed limits can be 75 (Nebraska/Wyoming) and 80 MPH (South Dakota). I drive a Chevy Impala 3.5 V6 flex fuel vehicle and on this trip burned the cheapest fuel available which ranged from 85 octane to E10 (no E-85 this trip). As I pulled in the driveway the trip computer showed exactly 29 mpg. Considering speeds, our load and mountain driving this is pretty darn good performance. EPA for this vehicle is 31 and under more normal driving conditions I have no problem reaching that number. When E-85 is about 35 - 40 cents/gallon cheaper than E10 I use it and do not experience the 20 - 30% drop many folks say they experience. That is probably because they are not actually doing a valid comparison and no two people drive the same way which has a huge effect on fuel economy. I might add this car now has 110,000 miles on it and other than replacing a water pump gasket and thermostat has had zero maintenance issues. My boats and collector cars have always run E-10, stored with protected E-10 and again I have never had an issue.

I appreciate your input and knowledge however while all you say is intended by the mfg it does not always come true. A good friend of a family member works for GM in their diagnostic area and several of their test vehicles have been modified to run straight E-85 and no gasoline. The performance is improved dramatically as well as fuel economy. In the future ....if E-85 continues it has been planned to offer specific fuel vehicles for better fuel economy and performance however, not knowing for sure if ethanol is here to stay or not (politics) GM does not want the liability of having the public put the wrong fuel into the vehicle and causing damage.
So these vehicles are on hold for the future. A family member had an opportunity to take a test drive in one of these vehicles and wow what a difference it made. I really wish we could get a fuel specific vehicle to the public, from what I have heard and also read the fuel economy is out there, just not marketed yet.

 

[Silvertip]

I appreciate your input and knowledge however while all you say is intended by the mfg it does not always come true. A good friend of a family member works for GM in their diagnostic area and several of their test vehicles have been modified to run straight E-85 and no gasoline. The performance is improved dramatically as well as fuel economy. In the future ....if E-85 continues it has been planned to offer specific fuel vehicles for better fuel economy and performance however, not knowing for sure if ethanol is here to stay or not (politics) GM does not want the liability of having the public put the wrong fuel into the vehicle and causing damage.
So these vehicles are on hold for the future. A family member had an opportunity to take a test drive in one of these vehicles and wow what a difference it made. I really wish we could get a fuel specific vehicle to the public, from what I have heard and also read the fuel economy is out there, just not marketed yet.

If the vehicle is designed to ONLY run on E-85 then yes, that's one thing. But flex fuel vehicles MUST run on Regular, E10, perhaps soon on E15 and E85. That is totally a horse of different color. And I also remind folks that E-85 was NEVER touted as a more economical fuel. It is an ALTERNATIVE fuel and is more economical only in situations I previously described. Good heavens, spark ignition engines have been designed over the years to run on gasoline, kerosine, diesel and for all I know, whale oil. Some WWII military vehicles would run on anything that burned. E85 is not available in all areas of the country but here in the midwest (corn country) it is readily available. There are three stations in my area (26,000 folks) that have E85. In some areas of the country E85 is much more expensive than regular so why anyone would use it (other than a government mandate of course) is beyond reason. Here in Minnesota state vehicles are required to use it when available but I suspect highway patrol and police departments are exempt,.

 

[thumpar]

Silvertip made a good point. It is expensive. The amount of fuel it takes to produce a gallon of ethanol is about the same as you get out. Corn is not the ideal source. In Brazil they use sugar cane. The fuel is very cheap.

 

[Scott Danforth]

Sugar cane and sawgrass make excellent sources for ethanol. Corn does not (power to refine is higher than output).

However the OP was commenting on fuel economy differences which we all agree... E0 is more economical than E10 in cylinder fires per gallon.

I agree there are alternative fuels for both SI and CI engines, however they currently are not as efficient as dino squeezings in today's common and readily available internal combustion engines.

I'm all for biofuels based on the best sources (sugar cane, cow pooh gas, landfill methane, etc). I simply want a choice at the pump that stands on its own as a viable source, and not one that exists only because of mandate (and one that takes more BTU's of natural gas per unit than we get out of it in liquid fuel)

 

[Silvertip]

Sugar cane and sawgrass make excellent sources for ethanol. Corn does not (power to refine is higher than output).

However the OP was commenting on fuel economy differences which we all agree... E0 is more economical than E10 in cylinder fires per gallon.

I agree there are alternative fuels for both SI and CI engines, however they currently are not as efficient as dino squeezings in today's common and readily available internal combustion engines.

I'm all for biofuels based on the best sources (sugar cane, cow pooh gas, landfill methane, etc). I simply want a choice at the pump that stands on its own as a viable source, and not one that exists only because of mandate (and one that takes more BTU's of natural gas per unit than we get out of it in liquid fuel)

And I don't disagree with that philosophy. However, I will take advantage of whatever is made available to me provided it fits my needs at the time. There are lots of things we buy that are subsidized but don't give a second thought about. How about other farm programs that pay farmers NOT to grow things. How about the solar industry and electric car manufacturers just to name a couple. These subsidies may lead to very real long term benefit down the road so they are not always a bad thing. If you want to scare yourself, visit the U.S. Government Grants web site sometime and see the wasteful research being funded.

 

[Scott Danforth]

we have 3 active programs at work that are grant funded.... I agree that many are wasteful research.

 

[Ryland3210]

I believe my comparison is valid. I did have a flow meter to measure real time consumption. The meter also kept a cumulative total The comparison was done several times over hundreds of gallons of fuel. Results using the real time correlated with the tank fill ups against the cumulative total gallons consumed. For all these reasons, I am confident in the results. Of course, this is based on a 2003 engine. It does have a knock sensor, so presumably timing was advanced more with the E10 than E0, although I could not monitor this.

In the olden days, straight alcohol was used to increase power in race and dragsters before nitromethane became available along with engine modifications to use it. I have an ancient British textbook on competition engines indicating the carburetor jets must be increased considerably to use alcohol over gasoline.

 

[HT32BSX115]

I believe my comparison is valid. I did have a flow meter to measure real time consumption. The meter also kept a cumulative total The comparison was done several times over hundreds of gallons of fuel. Results using the real time correlated with the tank fill ups against the cumulative total gallons consumed. For all these reasons, I am confident in the results. Of course, this is based on a 2003 engine. It does have a knock sensor, so presumably timing was advanced more with the E10 than E0, although I could not monitor this.

In the olden days, straight alcohol was used to increase power in race and dragsters before nitromethane became available along with engine modifications to use it. I have an ancient British textbook on competition engines indicating the carburetor jets must be increased considerably to use alcohol over gasoline.

This has been argued for as long as E10 has been available.

I have to disagree with your comparison............ Mainly BECAUSE your fuel flow differences are not valid. (I have one of those fuel flow meters too. they are not all that reliable) E10 will not produce huge differences in fuel flow in todays engines.

A 2% increase in fuel flow at 10 gallons per hour is 0.2 gallons! a 20% increase would result in a fuel burn of 12 gallons per hour. With ANY planing type boat powered by todays V-8 engines , it only takes a minute change in throttle position to increase the fuel flow by 2 gal/hr AND the corresponding change in speed is barely measurable!

All you would have to do is change the load (weight) and drive angle and you wouldn't get a speed increase at all.


Ethanol free fuel is available here in Wa for slightly more cost...........

If the above were true we would ALL be getting similar results. And we're not.....I have tried the same comparison and didn't see significant differences at all............. A 2% difference in energy content doesn't produce a 20% energy output difference (and corresponding throttle position increase) in any spark ignited engine. AND if you do have a knock sensor, it would likely advance (or allow advance) where it would normally retard a bit. That would also 'make-up" for a slight loss due to knock detection.

Your anecdotal "test' is not really valid because you simply cannot reproduce the same engine load every time you run the boat.

There's only one way to do it, and that's put the engine on a dyno so you can measure the torque and RPM accurately along with the fuel flow (using an accurate meter) Only then could someone produce repeatable results. and no test has shown a 20% increase using E10.

With all the political "stuff" aside of why we're being forced to "swallow" this fuel (pun intended).............The differences are not really enough to worry about. Many of us have 20+ years of experience of running it with no real problems at all. I don't even use snake oil in the fuel when I store the boat..........


Regards,


Rick

 

[Ryland3210]

I think there is a misunderstanding. The difference in fuel flow was more like 20%, not 2%. I would agree that 2% variation would be difficult to draw conclusions from, but that wasn't the situation. I have long term experience with the Flowscan meters and have tested them using calibrated containers to compare what it said to the actual measured flow rates. They easily met the manufacturer's specs within the 2% claimed. The cumulative totals are simply derived by adding up the pulses from the sensor, so if the flow readings were wrong, the cumulative totals would be wrong. That was not the case. The total gallons consumed according to the meter was also compared to the pump with close agreement. I stand by my data. When the same results show up over several tankfuls (about 60-70 gallons each time) it is extremely improbable that the meter would always read much higher for E10 by mistake.

 

[thumpar]

I think there is a misunderstanding. The difference in fuel flow was more like 20%, not 2%. I would agree that 2% variation would be difficult to draw conclusions from, but that wasn't the situation. I have long term experience with the Flowscan meters and have tested them using calibrated containers to compare what it said to the actual measured flow rates. They easily met the manufacturer's specs within the 2% claimed. The cumulative totals are simply derived by adding up the pulses from the sensor, so if the flow readings were wrong, the cumulative totals would be wrong. That was not the case. The total gallons consumed according to the meter was also compared to the pump with close agreement. I stand by my data. When the same results show up over several tankfuls (about 60-70 gallons each time) it is extremely improbable that the meter would always read much higher for E10 by mistake.

Or you have an issue with a sensor on your engine causing the increase. There is not way it would change by 20% unless something is wrong somewhere else.

 

[HT32BSX115]

it is extremely improbable that the meter would always read much higher for E10 by mistake.

You have to admit though, it seems a little strange that nearly all the rest of us would not see a significant increase in fuel flow using E10...... (20% would be pretty hard to ignore)

Since you didn't account for accurately measuring the actual load on the engine (which is really only possible on a dyno) , it would lead me to suspect your 20% increase in fuel flow is due to something other than fuel....

 

[Ryland3210]

FWIW. Ran a test on a full tank of gas in my Chevy Silverado. Similar (BUT NOT IDENTICAL, I CONFESS, and NOT ON A DYNO) driving conditions.
Mileage was 8% better on the zero ethanol on 450 miles of driving. I agree that 20% on my boat is difficult to believe. When Spring comes, I will run another series of tests. Here is a possible explanation: The 91 octane 0 ethanol allowed much more advanced timing than the 87 octane 10% ethanol. If the base timing (which I had not checked as the boat was delivered), may have been retarded versus the spec 8 degrees. If the 91 octane allowed spark to advance from, let's say, 0 to 20 degrees, that would make a huge difference in efficiency. Other than that theory, it is difficult to think of something wrong with the engine that would be triggered only when using 10% ethanol. I suppose nothing is impossible. I think I'll move on and see what happens next spring. Thanks for all the comments.

 

[bruceb58]

Typically, the engine in your Silverado would be setup for 87 octane and the timing is set accordingly. The engine is not set up to keep on advancing until a ping is detected. It is set up to retard when a ping is detected so it can't optimize for higher octane. That is of course different for an engine that comes from the factory spec'd for higher octane. It will have the timing initially set for higher octane.

I can drive my truck on the same route with identical gas and get varying fuel mileage. Too many variables.

In my Lexus which is designed for 91 octane, I seem to get better mileage when I use 91 vs 87 octane but too many variables again. Both fuels have ethanol.