I used to get angry when misinformation is spread by people who should know better, but my affection for Tom and Ray is stronger than that.
I converted my 1999 Subararu Outback to Flex-Fuel almost two years ago, and I am a very happy camper.
The penalty in MPG in my car is only 15%, not 30%. I am a retired physicist, not an automotive engineer, but maybe it is because the 105 octane of E85 allows spark advance beyond that of gasoline.
Yes, MPG is lower, but who cares! MPD is what counts (miles per dollar). Last year the price of E85 ran consistently 25% lower than that of regular gasoline. This year it’s a wash or worse, so I use E10. Flex-fuel is like that; it is FLEXIBLE; use whatever ratio is best for you at the time and your on-board computer will adjust.
Wait a few years and gasoline will be $10 a gallon and I will be paying a lot less.
Contrary to what Tom and Ray said on the air, performance on E85 is BETTER than that on gasoline. Horsepower is noticeably higher at high speeds and torque is better at low speeds.
The “experts” online assured me that E85 would eat away my fuel lines and pump. WRONG! The car still runs fine with the adapter I installed ($400 for 4 cylinders). Installation is easy if you can reach your spark plugs, since all you do is to switch some ignition wires around. I had to remove the air filter to reach them.
So don’t knock E85 until you get some experience guys. Otherwise you make fools of yourselves.
Yes, but Ken hasn’t gone far enough in researching operating expenses. The owner’s manual of my flex-fuel 2001 Sonoma says oil change interval goes from 7.5k/6mo on gasoline to 3k/3mo on E85. Spark plugs and fuel filter intervals were similarly shortened for E85.
If gasoline is $3.00/gallon, E85 has to be less than $2.00/gallon before one can come close to breaking even.
Know the energy content equations don’t justify my results but have recently started paying a bit more for ethanol-free gasoline and am seeing 4% to 10% MPG improvement. From ~52 MPG to 58 MPG on 2007 Prius. Costs $0.05 to $0.10/gallon extra over the discount brands but still less than Shell. Then again Shell is the most expensive brand locally while Chevron is mid-pack and about the same as the no-name ethanol-free.
Well Dave why don’t you do a little research so we don’t have to listen to just what you “bet”? or perhaps you have another agenda, one that is different than providing helpful information.
I routinely do a lot of research before I post as I feel factual information best serves the public.
No not all all, I am not saying they get the same mileage. I am saying the car will get the mileage (or very close) to what is posted.
If your posted figure is for using unadulterated gasoline and you switch to E85 you will get less but there is no reason to say posted figures for a E85 car are any less reliable than posted figures for a unadulterated gasoiline vehicle.
The question was not worded, " Will I get poorer mileage than posted when my flex fuel vehicle was tested using unadulterated gasoline if I switch to E85"?
It was just a poorly worded “Does E85 lower your MPG” and I answered “your E85 car should get the posted mileage”.
Modern cars with an onboard computer, knock sensor, oxygen sensor, and mass flow sensor try to adjust the richness of the fuel/air mixture adjusting the duration of fuel injection at each cycle. Since the energy density of E85 is lower than that of gasoline, the firing pulse must be stretched beyond the capacity of many systems.
The adapter is a chip that stretches the firing pulse. There are two wires coming out of the little box containing the chip: One removes the existing ignition cable from the spark plug and connects one of the adapter cables to the spark plug and the other to the original cable.
Thank you for being only slightly sarcastic. I was expecting worse.
CU did their article on a Chevy Tahoe, which at that time had lousy fuel management. CU concluded that E85 was a scam. My conclusion is, don’t buy a Chevy Tahoe unless you find evidence that they cleaned up their fuel control system.
Many magazines have argued simply from the 30% lower energy density of E85 that the laws of thermodynamics require 30% lower mileage. They seem to have forgotten that the efficiency of internal combustion engines is of the order of 20% and most of the energy is wasted in the form of heat. Improve the efficiency a little bit and you get better mileage. Few magazine writers have actually tried E85 to the point of measuring the fuel efficiency.
I measured the efficiency in my Subaru and reported the results. If you want published results, Google the University of Minnesota. They did the research and have more than one paper online.
Or try it yourself. You won’t hurt your modern car with, say, E50. (Mix it yourself at the pump.) Your malfunction light may come on, complaining about lean fuel, but it will go out on its own when you switch back. (I bought a cheap code reader.)
You might also Google Saab’s Flex-fuel sports car. You will find data on
horsepower and torque.
I haven’t seen any research on these questions by the EPA.
The main reason I switched to E85 was not my cost but macroeconomics. The US imports oil at the rate of about $7,000,000,000 per year. That’s on the same scale with the damned stimulus package. And much of that money is going to folks who don’t like us very much.
I don’t like to pay them to buy the weapons with which to attack us.
The total energy inputs to produce ethanol is about 80% of the energy it delivers. Not a great deal, but it does not take more energy to produce than it delivers!
On the other hand, it’s NOT CARBON NEUTRAL, unless all the electricity involved to produce the inputs comes from hydro, nuclear, or other renewables. Many other inputs are fossil fuel, natural gas, chemicals, etc.
The question here is twofold: the long term commitment of farmland to fuel production, resulting in future food shortages, and the extremely inefficient coversion process which uses only the seed, and not the rest of the plant.
Ethanol’s contribution to reduce global warming is miniscule, whether you believe in global warming or not.
Future biofuels will come from seaweed, algea, plant cellulose and still from sugar cane, which needs minimal energy inputs, and also produces an edible animal feed with what’s left over.
In short, corn ethanol fuels are a bad deal for the US overall.
The problem with “Flex-Fuel” engines is that they still must stick with 9 to 1 compression so they can run on 87 octane gasoline. An E-85 only engine could use much higher compression and regain much of the mileage reduction. An E-100 only engine could use higher compression still and suffer little or no loss in fuel mileage over a 9 to 1 compression gasoline engine…But at the moment, the market is just to limited for alcohol only high compression engines…Buy the way, E-85 is rated at 105 octane and can support 12.5 to 1 compression and pure ethanol is 115 octane and can support engines having 14 to 1 compression ratios…
The best published study is by Minnesota State Univerity at Mankato. They tested ethanol/gasoline mixtures over a wide range of concentrations and 5 different makes of automobiles.
The MPG varies considerably over the makes of vehicles. As I recall, there was one combination of concentration and car make that gave MPG better than pure gasoline.
In some makes, the MPG was reduced by 30%, as texases says, but in others it was not.
Note that internal combustion engines produces much more heat than motion. The burning characteristices of ethanol are quite different from those of gasoline. In particular, the octane is much higher for ethanol. The effect in modern computer-control engine systems is to permit a greater spark advance with ethanol than with gasoline.
Whatever the reason, my Subaru Outback, 1999, converted to flex-fuel, gets 15% less MPG, not 30%. And in 2008, the price of E85 was regularly 25% lower than that of E10. The result is that my miles per dollar was better on E85 than on E10. (In 2009, the price is less favorable to E85, so I use E10.)
Performance was better also, in spite of the unchanged compression ratio of the engine. Horsepower was somewhat higher, as was torque. Saab makes a flex-fuel sports car, the ads for which give precise data on comparative performance.
“In short, corn ethanol fuels are a bad deal for the US overall.”
Consider that the US pays about $70 billion per year to foreign oil states for oil. That’s a huge amount – of the order of some stimulus package EVERY YEAR. Some of these states are not our friends; we are paying some of them money with which to arm themselves against us.
Correction: The studies that tested several makes of car and several ethanol concentration are from several years ago and were done at Minnesota State at Mankato.
U. of Minnesota has also done studies but they are more concerned with pollution and economics of land use. They are also quite controversial.
When I use BP regular containing up to 10% ethanol in my V6-Dakota ,it runs great ,seems to run a little better-but the caveat is,less mileage,which is entirely reasonable considering the lower BTU content of the mixed fuel(my experience anyway).I used to try to find vendors in the 90’s that sold gas containing ethyl alcohol,because of the trade deficeit.Very few then, anyway in the future we will have to find a median approach to fuels.I’m in favor of synfuels and the hybrid approach for fuel conservation(as long as it is cost effective.I guess we really need to start driving smarter and perhaps a little less)-Kevin
Yes its still oxygen but why would the amount (which is what the mass airflow sensor measures) for E85 be the same fo unadulterated gasoline? And why would the values the 02 sensors present to the PCM when burning E85 be the same values when burning gasoline.
Mind you I don’t dispute the fact that programing can be written to run either fuel with the same sensors but I would expect the “what the PCM wants to see and what it is seeing” would not be the same for both fuels. I can’t see trim values being the same, what I mean is when a too rich or too lean condition is detected the correction (trim value counts) would not be the same with both fuels, hence different PCM programing for E85 or gasoline. I really do wonder how its done.