Mileage change with ethanol fuel?

[Drifter]

Now that gas without at least 10% ethanol is impossible to get... in fla anyway! How many of you noticed a loss of mileage? If so what is the difference between the 2 fuel types. It seems some bikes dont like it at all and others not much change. How about KLRs?

Is there any state left where you can still get 100% gas?

[RichLockyer]

Yup.
Ethanol's raw octane rating is around 117, so it's a "good" antiknock additive, but it's BTU content is about 25% lower than gasoline, so if the fuel is 10% ethanol, you can expect a 2.5% reduction in power and fuel economy.

More if it's wet. Ethanol, like all alcohols, is hydrophilic. In it's raw state, it can be up to 30% water by weight. In solution with gasoline, that drops to about 3-5%... but that's STILL the potential for the fuel in your tank to be between 0.3% and 0.5% water.
Dad used to keep a 5 gallon jug of fuel in the garage for the lawn mower. Refilled it about once every 3 years.
I've had gas for my dirtbike "turn" in as little as 3 months... total crap out of the can, and HEAVY green powder-like deposits on the brass parts in the carb. Completely plugged my idle circuits. Sta-Bil seems to take care of it.

Ethanol sucks... and the only reason it's "cheap" is because of government subsidies.

We aren't seeing any difference out here in Kalifornistan because before Ethanol we've had MTBE since the mid '80s... which did the same thing but they found that it was poisoning the groundwater.

[Nate]

Kansas still offers 100% gas at the pump. Even though I raise corn I only put pure gas into my bikes.

[sbg8r]

Originally Posted by RichLockyer

Yup.
Ethanol's raw octane rating is around 117, so it's a "good" antiknock additive, but it's BTU content is about 25% lower than gasoline, so if the fuel is 10% ethanol, you can expect a 2.5% reduction in power and fuel economy.

More if it's wet. Ethanol, like all alcohols, is hydrophilic. In it's raw state, it can be up to 30% water by weight. In solution with gasoline, that drops to about 3-5%... but that's STILL the potential for the fuel in your tank to be between 0.3% and 0.5% water.
Dad used to keep a 5 gallon jug of fuel in the garage for the lawn mower. Refilled it about once every 3 years.
I've had gas for my dirtbike "turn" in as little as 3 months... total crap out of the can, and HEAVY green powder-like deposits on the brass parts in the carb. Completely plugged my idle circuits. Sta-Bil seems to take care of it.

Ethanol sucks... and the only reason it's "cheap" is because of government subsidies.

We aren't seeing any difference out here in Kalifornistan because before Ethanol we've had MTBE since the mid '80s... which did the same thing but they found that it was poisoning the groundwater.

I know boats hate the stuff

[RichLockyer]

Originally Posted by sbg8r

I know boats hate the stuff

Worst case scenario... Extremely high humidity environment results in the maximum absorption of water by the fuel.

If you're having trouble with fuel system components or corrosion, it IS possible to force the ethanol out of solution, but it's not easy and will "waste" about 15% of your fuel....

Put 4 gallons of fuel in a clear glass 5 gallon jug (available from homebrew suppliers). Dump in 1/2 gallon of water. Shake well, let it settle out overnight.
The water and ethanol will settle out to the bottom of the bottle.
Notice that you put in 1/2 gallon of water and you have a gallon of "clear" at the bottom? You can siphon the gasoline off of the top with a racking cane, or if you are using a conical fermenter with a draincock at the bottom, drain the water/alcohol mix from the bottom, then transfer the remainder into a fuel jug.

Not something you want to do for a 200 gallon tank, but possible.

[TripleDigitRide]

We have the same problem in TN. It's getting more and more difficult to find real gasoline. I did a little digging, and found that Sam's Club offers non-ethanol.

I'm not sure about all states, but here in TN, you don't have to be a Sam's Club member to buy their gas.

[Sidekick]

I only put high octane fuel in my Drifter but a KLR will burn almost anything. Although I do get a little bit better mileage with the higher octane it usually only drops it from 50 mpg to about 46. Although my right hand could be a bigger factor than anything....

[Hot Cruiser]

Since our gas now has 10% ethanol rather than MTBE the highway mileage in both of our Honda CR-Vs has dropped from the 29mpg range to the 26mpg range. Doesn't make sense - the roads, speed limits, and our driving habits are the same, but I keep meticulous mileage records and those are the facts. Other local drivers are complaining about getting the same sort of results, about a 10% decrease. Makes the feds and state happy - more tax revenue, and of course there are the oil companies as well. To rub salt into the wounds, ethanol production is subsidised by our taxes.

[Utah Motorcyclist]

Originally Posted by Sidekick

I only put high octane fuel in my Drifter but a KLR will burn almost anything. Although I do get a little bit better mileage with the higher octane it usually only drops it from 50 mpg to about 46. Although my right hand could be a bigger factor than anything....

It should be the opposite. The lower octane has higher energy potential.

[RichLockyer]

Originally Posted by Utah Motorcyclist

It should be the opposite. The lower octane has higher energy potential.

Octane has nothing to do with power.
Octane is the fuel's resistance to initial combustion under compression... effectively, it's flashpoint.

A higher octane fuel will be less likely to be ignited by a "hot spot" in the cylinder, perhaps from the edge of a valve, or a piece of carbon.

Once ignited, the flame front burns at roughly the same temperature regardless of octane and it will progress across the piston.

The energy potential of a fuel is revealed by it's BTU content...
Gasoline is 114,000 btu/gallon
"Winter" blend is 112,500
E10 is 111,836
gas/ETBE is 111,811
gas/MTBE is 111,745
E85 is 81,800
Ethanol is 76,100

So a gallon of E100 contains 66% of the energy of a gallon of gasoline. It is coincidental that it's octane rating is higher (it's not 150% higher)... that has nothing to do with the energy content of the fuel.

[RichLockyer]

As far as fuel economy vs octane.... there should be no difference on a bike, or a vehicle with an old-style ignition system.

On vehicles with a knock sensor, it is possible to get better MPG on higher octane fuels, because the ECU will retard the spark timing when it senses knocking, which reduces cylinder temperature/pressure... reduced knocking, but also reduces MPG.

[northernman]

I know for a fact that my KLR gets worse mileage if i have to fill up with ethanol blend gas.
I have had to a few tank fulls, and I am switching to reserve 30 to 40 kms earlier on average, than with good old gas.

And an engine that is capable of running fine on regular is best run on regular, and yes it does make more power on reg than premium, if it does not knock or ping.

The resistant to ignition of prem, also robs it of some power making potential....Would it be noticeable in normal bike riding lets say.....Doubtful, but in extreme high load cases, where you can measure it, yes it makes less.
Say strapped to a dyno, or in the case of sleds, where they cannot pul their full required rpm clutched as they were on a hard, deep snow climb.
2 strokes are more affected than 4's i notice.

[solitary]

My observations 1982 GPz 550, logging every single fill-up:
2006 (99% gasoline, 1% additives): 47-59 mpg (starting ODO 20,893)
2008 E10: 46-56 mpg (ending ODO 38,53.

So for me, no difference worth noting.

[twhite]

ethanol doesnt have the btus that straight gas does. Expect a little loss of power and not quite the mileage. Noticeable on my c-14, but not that much different. ride hard

[tricker]

10% caused me to lose 8-10mpg

[Hot Cruiser]

Crappanol - sorry, ethanol - above message +1

[Hot Cruiser]

Originally Posted by RichLockyer

Yup.We aren't seeing any difference out here in Kalifornistan because before Ethanol we've had MTBE since the mid '80s... which did the same thing but they found that it was poisoning the groundwater.

An amazing state, California - not too long ago they made nearly every service station replace its underground gasoline storage tanks because they supposedly were leaking gasoline containing MTBE and contaminating the groundwater, in the process putting a lot of independents which sold price-busting gasoline out of business (sounded like a plot by Big Oil) . . . then after those stations which could afford it replaced their tanks MTBE was banned . . . brilliant!

[RichLockyer]

In addition to the tanks seeping, they were also concerned with reservoirs. Ever since they determined that MTBE was bad for water, they started mandating that MTBE-bearing fuels not be sold at marinas (but it was still oxygenated with crapanol), but the vast majority of pleasure craft do not fuel up at the "beer dock" because marine gas is $0.50 to $1.00 higher than pump gas. No highway taxes, but the harbor fees/taxes are higher.

Boats that are trailered in are fueled on the street, and even boats that are docked 24/7 are frequently fueled with pump gas. My buddy's 22ft Whaler has an 80 gallon tank and I've made a LOT of trips between the gas pump and his back yard hauling 5 gallon containers.

Funny thing is, the marine taxes on gasoline don't translate to marine Diesel... it's the red "off-highway" fuel, but it's about $0.50 cheaper than street Diesel.

[mrbill00]

at least 10% loss in cars and motorcycle...Georgia....and will mess up a lawn mower when it sits from Nov to Mar.

[ta5ryan]

Originally Posted by Drifter

Now that gas without at least 10% ethanol is impossible to get... in fla anyway! How many of you noticed a loss of mileage? If so what is the difference between the 2 fuel types. It seems some bikes dont like it at all and others not much change. How about KLRs?

Is there any state left where you can still get 100% gas?

I have been running 10% ethanol and have noticed no change, still getting about 50 mpg (sometimes more depending on how I have been driving).