So forgetting about the cost difference for a second, at the least you get... about 50 miles less per full tank?/ Which means filling up more often, something I wouldn't want to do this time of your year, or before or after work. More importantly, if you had a road trip/extended drive planned, you would want to run 3-5 tanks to clear the e85 out? I have a 26 gallon tank, I sware I have read that you have 2 or 2.5 gallons in reserve after the light comes on, but not sure how much of that would "already be in the lines"... I have put 26.8 gal in before...
Should I try running E85? Or stick with unleaded.
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James, a couple of friendly math corrections. Divide the cost per gallon BY (not into) the mpg. Another way to say that is to divide the mpg into the cost per gallon. And the result is 16.48 cents (no $ sign) or $0.1658, not 16/100 of a cent per mile. (My discipline is to use either the dollar sign or the word cent, but not both. That minimizes my confusion.)
Scottydoggs
Full Access Member
flex fuel cars/trucks can run a mix of e85 and gas with no issue, the truck has a content sensor, it will figure out whats in the tank all on its own and make the necessary adjustments.
And know that when you buy E85, you may not get 85% ethanol. Pumps are usually marked "up to" 85% ethanol content.
swathdiver
Full Access Member
For GMT900 with 26 gallon tank, the low fuel light comes on when 4.3 gallons remains in the tank. It takes fewer tanks of gasoline to minimize the alcohol content, usually 2; as you know it already contains up to 10% ethanol.
Thanks, I could not figure out why some people were confused by my math! LOL
Only with E85R can one get 85% alcohol, the other 2% is best explained by this quote, "The 85 percent doesn’t refer to pure ethanol, but to denatured fuel ethanol which already contains 2% hydrocarbons to make it “unsuitable for beverage use under a forumla approved by a regulatory agency to prevent the imposition of beverage alcohol tax."
http://injectordynamics.com/articles/e85/
So if you ran even just the one tank before down to the reserve light, then filled up with gas, at the most you would lose 10 miles or less of total range per tank?
Scottydoggs
Full Access Member
low light has about 4 gallon reserve, wont make a difference to the truck. why its called flex fuel, you can mix 1/2 a tank of corn and 1/2 gas if you wanted to.
so roughly 4 gallons of e85 with a tank of gas wont likely hurt the mpg to much.
so roughly 4 gallons of e85 with a tank of gas wont likely hurt the mpg to much.
Martinjmpr
Full Access Member
I have found this to be the case with my '04 Suburban. Just for fun, I put in a full tank of E85 before going on a camping trip. This trip required me to pull a 3500lb trailer through Eisenhower Tunnel (the highest point on the US Interstate Highway system, 11,000' above sea level.)
With E85 it felt like rocket fuel compared to the rot gut E10 I normally use! It didn't hurt that it was $0.60/gallon cheaper.
Then, on the way back home, just for fun I put in a tank of 91 octane (91 in Colorado is the same as 93 in the flatlands, higher altitudes reduced the octane so 91 is our "premium..") for the trip back over Wolf Creek Pass (10,600'.) Unlike my E85 experience, I did not find any comparable benefit to running 91 octane over 85 (our low octane, equal to 87 at lower altitudes.) And the cost was $0.80 MORE than 85 octane E10.
Since I obsessively track my MPG I have developed a rule of thumb that goes like this: In order to have an equivalent "cost per mile", E85 needs to be at least $0.65/gallon cheaper than E10. There are only a few local stations that have E85 and I keep track of them on the Gasbuddy.com app. Right now the delta between E10 and E85 is $0.50 or less, so it makes sense to run E10.
But if I were to be headed over the mountains with the trailer, I'd put E85 in just for the extra power going over the pass.
Matthew Jeschke
Full Access Member
I am kind of dumb as i had assumed was 85 octaine. My dad liked to put a little in his non e85 truck every now and again. He said it would clean out the motor. He is not a mechanic but rather a chemist. I think biggest concern with non e85 motor is it burns hotter right? Could damage valves in theory on a non e85 motor?
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Scottydoggs
Full Access Member
burns cooler iirc. i know a lot of people who run e85 on non flex cars. requires a injector upgrade and tuning. what it comes down to is, any engine can run it if you set up its needs.
Martinjmpr
Full Access Member
I don't know what the octane of E85 is but it's high. Maybe 95 or 100.
If E-85 marketers were smart they'd put the octane rating on there. It would sell like crazy. "Look at this fuel! It's 95 octane! That means it will make my car go faster!"
swathdiver
Full Access Member
I don't know what the octane of E85 is but it's high. Maybe 95 or 100.
If E-85 marketers were smart they'd put the octane rating on there. It would sell like crazy. "Look at this fuel! It's 95 octane! That means it will make my car go faster!"
They'd have to tighten up on the ethanol content to do that. It can be anywhere from 51% to 83% and that's why they officially call it FlexFuel now instead of E85 though both are used in marketing.
Pure ethanol has an octane rating of 113. E85 is anywhere from 99 to 105 depending on the grade/quality of gasoline it was mixed with. Sometimes it's mixed with 85 octane gasoline.
E70 is winter blend and that's what my motor has been seeing, 72%-76% since October.
To the OP I would not run E85 in an older flex fuel vehicle with that many miles that has never used it. Personal Experience here: 2002 Ford Taurus "grocery getter" that my son inherited from his mom after she had driven for 150k miles strictly on regular fuel. Kid sees yellow cap and researches and sees that it is a flex fuel engine so he tries a few tanks of E85 because it was cheaper. Result was the car exhibited hard starts and rough idle. Went back to regular fuel and symptoms disappeared. Now it is possible that if he had preserved it would have straightened out on its own but to me it was silly to use it with basically zero to gain and the possibility of having to do work on the fuel delivery system. (could have been a bad ethanol content sensor etc)
Repeat, I would not take a chance on a high mileage OLDER flex-fuel vehicle that has not been run on E85. Just my personal opinion.
Note: I had a 2014 GM 5.3 and it liked E85 but I had started using it occasionally when it was new, mpg was poor and any performance gain was minuscule it did not impress.
Repeat, I would not take a chance on a high mileage OLDER flex-fuel vehicle that has not been run on E85. Just my personal opinion.
Note: I had a 2014 GM 5.3 and it liked E85 but I had started using it occasionally when it was new, mpg was poor and any performance gain was minuscule it did not impress.
BigVette427
Member
Ethanol is a joke propagated by the corn lobby in Iowa. If the consumer had the option to buy gas with an without blended ethanol, the ruse would be up in months. It's only profitable when the crony pols force refineries to put it in our gasoline via law - crony capitalism.
Charles Land
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I have run E85 occasionally in my 2011 6.2l Denali. I get about 20% lower fuel mileage, so unless the price of E85 is 20% or more less than regular, I don't buy it. I have wondered if the alcohol based E85 would do anything to cleanup the injectors (which will gum up after awhile on regular gas). I think it might, but am not sure.
swathdiver
Full Access Member
I shared your sentiments for years and for the most part still do. Ethanol should not be propped up by the government nor should we be forced to use it in our regular gasoline. When the mandate took effect, I remember losing 2 mpg. However, Justin at BlackBear pointed out that it makes engines more resistant to detonation and knock.
I like it for the increased performance and keeping the motor clean but often switch if the prices get to where it doesn't pay to burn it. Right now it's still a wash for me but will probably switch back to gasoline after we go racing.
Free Enterprise should decide, not government.
Check out this article on E-85. Maybe it will help you decide. Not all is rosy with Ethanol.
http://www.speedhunters.com/2015/04/everything-you-need-to-know-about-ethanol/
http://www.speedhunters.com/2015/04/everything-you-need-to-know-about-ethanol/
swathdiver
Full Access Member
The warnings in this article pertain to customized racing engines and programming. It is not an accurate assessment of how E85 interacts with FlexFuel vehicles designed to run on any amount of Ethanol from 10% to 85%.
Once again the warnings about water getting into the fuel system and rusting out the fuelp pump and what not. I wonder how much if any water is in my tank after 586 gallons and letting the truck sit for days at a time with 2/3 of the tank empty? On average, she's refueled every 8 days.
Scottydoggs
Full Access Member
this guy in the link there has a bunch of tuning vids on youtube, if you understand tuning just a little bit, he talks you through what hes doing while hes tuning a car on a dyno and you see what the changes did in real time, and he makes it all simple sounding too.
im willing to bet if your son had ran one more tank of e85 the content sensor would have caught up to the fuel, or maybe it needed the fuel trims reset. and ill say it,,,,its a ford lmao. i hate fords.
i know more then a few people who tuned and run their cars on corn year round, the hard starting in cold weather is a tune issue. with a tuner its fixable.
in a flex hard starting is likely the content sensor still learning. its not like you flip a switch and all just works.
also if you have a inline fuel filter and start running e85, change the filter a few times, like with each new tank 3 times works for most, the e85 will clean your tank out of the crap in it, clogs the filter up pretty fast. ive read posts of guys stuck on the side of the road over a filter more then once.
Spacido
Full Access Member
I bring my contribution: All my vehicles drive at E85. My 2001 Tahoe rolls at 50/50, beyond, the engine light comes on.
Conversion boxes or computer reprogramming are quite common in France. Others prefer to run their V8s with LPG.
For now mine is not reprogrammed. My fuel consumption is 16 mpg with gasoline and 14.7 mpg with 50/50, it allows me a saving, given the price of gasoline here.
My Tahoe behaves quite normally and starts very well even in cold weather. There is an American Truck Specialist here who reprograms the calculators to run at 100% E85. The calculation tables would already be preprogrammed in our trucks, it remains only to unlock this programming.
This results in more power due to the larger octane and it reprograms the automatic gearbox.
I say, for those who want to get ethanol, to drive about 1000 miles and then change the fuel filter. Ethanol has a high cleaning power and detaches impurities from the tank.
You have to switch to ethanol gradually. First 15% then 30% .... do not refuel at once
Conversion boxes or computer reprogramming are quite common in France. Others prefer to run their V8s with LPG.
For now mine is not reprogrammed. My fuel consumption is 16 mpg with gasoline and 14.7 mpg with 50/50, it allows me a saving, given the price of gasoline here.
My Tahoe behaves quite normally and starts very well even in cold weather. There is an American Truck Specialist here who reprograms the calculators to run at 100% E85. The calculation tables would already be preprogrammed in our trucks, it remains only to unlock this programming.
This results in more power due to the larger octane and it reprograms the automatic gearbox.
I say, for those who want to get ethanol, to drive about 1000 miles and then change the fuel filter. Ethanol has a high cleaning power and detaches impurities from the tank.
You have to switch to ethanol gradually. First 15% then 30% .... do not refuel at once
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