ethanol free gas - worth the extra money?

[pickler]

Gas station sells ethanol free 91 octane for 15% more money compared to E10 87 octane. is it worth the extra money if my car is fine with regular gas? I read somewhere that E10 gas causes up to 5% loss in fuel economy and damage to seals and gaskets.

 

[BrianPetersen]

Do the math with your own vehicle. 15% more money for (claimed) 5% better consumption is not worth it in the absence of any other factors.

If the vehicle is older than the 1990's then MAYBE there might be material compatibility issues. Newer ones shouldn't have a problem with 10% ethanol.

BUT ... If you are planning to store the vehicle for a while ... it may be worth filling up the last couple times prior to storage using the ethanol-free stuff.

 

[swall]

It is a religeous argument. But,I buy ethanol free gas when I can because the whole subsidized ethanol thing in the U.S. justs ticks me off.Took a motorcycle trip through Wisconsin and into the Michigan UP in August and there were lots of stations offering and advertising ethanol free gas. I think I ran 4 tanks.But, for the most part, my vehicles run fine on E10. One big bugaboo with E10 is long term storage of fuel. If you get as little as 0.10% water in the fuel, you can get phase separation. So, for outdoor power equipment, I keep the non ethanol stuff on hand.

 

[dgallup]

Never had a problem with E10, even in mower gas or leaf blowers that sit around for months. Unlikely the mileage penalty will be as high as 5%, 3% more like it. The only place I use "pure" gas is in boats & I still always put a stabilizer in it.

OLD vehicles can conceivably have a problem but if a 30 year old fuel pump diaphragm gives up the ghost, can you really say it was due to 10% ethanol?

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[pickler]

my car actually doesn't like E10 much even though it's fairly new. i noticed quite a bit of difference in throttle response with straight gas. But my worry is more engine longevity. I heard ethanol just corrodes stuff in there.

 

[TheBlacksmith]

There is a lot of concern from manufacturer's about a proposal to increase the ethanol to 15%, but generally most newer cars don't care. I don however, use the ethanol free in my power equipment; since I currently live in an apartment, I break out the chain saw and edger once or twice a year to help a friend. The high octane, ethanol free synthetic lube gas is like $4.50 a quart, but I've realized my time is worth something too and this avoids draining the system each time I'm done or fixing a gummed up system

 

[pmrobert]

Personal experience in a Mazda RX-8 is city mileage 17mpg w/E10 93 PON, 21mpg w/ Rec-90(ethanol free 90 PON). Using ethanol free in the car is a no-brainer - I can't use 87 or 89 in it and the 93 E10 and R90 are the same price. Neither causes counts on the knock sensor unlike the 87 and 89 E10. I have a Yamaha 90 horse 4 stroke outboard that I used to have to rebuild the carbs at least twice a year when using the E10. No chemical potions seemed to help and the boat is used at least 20 hours a month, sometimes much more. After switching to R90 full time 2 years ago I have experienced no carb problems whatsoever. The E10 fuel seemed to cause the very small holes in the emulsion tube to get clogged with something that only comes out with ultrasonic baths and shop air. I'm not happy with the US subsidized ethanol deal either.

 

[berkshire]

pmrobert wrote
I have a Yamaha 90 horse 4 stroke outboard that I used to have to rebuild the carbs at least twice a year when using the E10. No chemical potions seemed to help and the boat is used at least 20 hours a month, sometimes much more -- The E10 fuel seemed to cause the very small holes in the emulsion tube to get clogged with something that only comes out with ultrasonic baths and shop air.

This was/is my experience with E10 in outboard motors. In May 2011 I spent $1600 in a month on carb and fuel system parts. I had a fleet of 16 boats with 4 to 6hp 4 stroke motors, we had no problems with these until ethanol was added to gasoline. Current experience says if the motor is used every day the ethanol is a good thing keeping excess water out of the fuel. If the boat sits for a week then it is a bad thing, once phase separation starts. You get all of the evils pmrobert mentions.
I would say if you have the opportunity to get ethanol free gasoline for boat use, use it if the boat is going to sit between uses.
I personally side stepped the problem by switching to propane motors.
B.E.



You are judged not by what you know, but by what you can do.

 

[pickler]

i get occasional pinging and knock with any octane pump gas during the cold season. The winter gas here just sucks big time. during summer time though i find 89 octane E5 (5% ethanol) works fine in my car. again if i want ethanol free i have to move up to 91 AKI. I haven't been able to convince myself to justify the extra cost of premium gas. If there was ethanol free regular gas i would been happy.

prices here per liter:
$1.48 premium E10 (94 octane)
$1.44 premium ethanol free (91 octane)
$1.42 premium E10 (91 octane)
$1.36 midgrade E5 (89 octane)
$1.34 midgrade E10 (89 octane)
$1.26 regular E10 (87 octane)

 

[jagad5]

Run several tanks of both through your vehicle in "normal" driving conditions. For my cars, it has never been worth the reduced price (5% less for 10% lower mpg.) Ethanol is not the fuel of the future.

Doug

 

[dgallup]

I checked a couple of local stations, ethanol free is only available in 87 octane with a 10% price premium over 87 octane with 10% ethanol. Since there is no premium ethanol free I never use it in my car.

With 10% ethanol gas I get consistently better than the EPA highway estimate for my car driving long trips (500+ miles each way) on the interstates at 75+ mph. I keep the receipts and average over the entire round trip, I tend to drive the same routs several times a year. I think these are as accurate a measurement as you are going to get on the street. A little over 28 mpg in spring or fall and 27 mpg in the summer when the AC is working hard. Winter tends to drop into the high 26's but I run different tires.

http://www.fueleconomy.gov/feg/noframes/18332.shtml

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[FeX32]

I never use gas with Ethanol anymore. I have tried ultra 94 with 10% ethanol and 91 V-power with no ethanol. I consistently have obtained 1L/100km average fuel consumption better with the ethanol free gas.



Fe (IronX32)

 

[Lou Scannon]

While I'm no fan of the fuel ethanol boondoggle (or racket or whatever you want to call it), when used in engines designed for ethanol blended fuels, within the engine's designed range, there is no reason for ethanol blended gasoline consumption to increase more than about ([0.3]*[the ethanol fraction]) versus straight gasoline. E.g, for E10 (10% ethanol), fuel consumption should increase about 3%. Such a small delta is difficult to ascertain with statistical validity, and would typically require special test procedures and equipment [i.e. to get a statistically valid result].

"Schiefgehen will, was schiefgehen kann" - das Murphygesetz

 

[BrianPetersen]

I recently had a Ford Focus rental for a week - that car uses a 2 litre direct-injection engine and is a flex-fuel vehicle. I tried one tank of E85 just to see what happened. The car got 40-ish mpg on gasoline (probably E10) and 35-ish mpg on E85 (really probably slightly less due to remaining E10 in the tank).

On an energy-content basis, E85 has about 77% the energy content of E10, and the car seems to have done a little better than that. Ethanol is not a bad fuel, IF the engine is designed to run on it!

 

[pickler]

Any engine can run on e85. Any modern engine with sophisticated engine control unit. I have converted subarus to run on e85 just by software reflash. Yes ethanol is good because it reduces temprature and emissions so you can run more timing and boost (if turbo)...so power output goes up. However it reduces range, corrodes the internals and drives up food prices.

 

[Lou Scannon]

Yes, when the mix is heavily biased toward ethanol, and the spark timing is adjusted accordingly to take advantage of ethanol's superior antiknock behaviour, relative to pump gasoline; I would expect to see a thermal efficiency increase, observed as less reduction in fuel consumption than that based solely on volumetric energy content, as BrianPeterson reports.

"Schiefgehen will, was schiefgehen kann" - das Murphygesetz