Experimenting with E85

[A_Harman]

Nothing really radical, but new to me. My Buick Verano T has the flex-fuel capable LHU engine, and I am looking for a way to beat the high cost of gasoline. The 2.0L turbo requires 91 octane minimum, so I have to run premium all the time. If I'm patient enough, I will run two transactions at the pump to get 50/50 89 and 93 octane, which should be pretty close to 91. But most of the time, I'm in a hurry and fill it up with 93, that is running $5.00 per gallon.

Yesterday, I decided to try a half-tank of E85 mixed with the 93 that was in the tank. After 200 miles, the fuel economy seems to be comparable to straight 93, and the car is running fine. The E85 was $4.20, bringing my average per gallon fuel cost down to $4.60, with no apparent decrease in fuel economy.

I am planning to run it down to Empty and try a full tank of E85 next.
But the high octane of E85 has me thinking about blends with the lower grades of gas. Online sources quote different values, but the prevalent number seems to be 105.
A 50/50 blend with 93 would give 99 octane, and is overkill for my daily commutes.
A 50/50 blend with 87 would give 96 octane, which would still be more than the engine needs. Regular is at $4.00, and would allow a further slight reduction in cost, while putting more energy into my tank.

Seems like it's worth a try.

 

[Skippy722]

I’d definitely try blending e85 and 87, but you need to be careful because E85 isn’t always E85. It can be as low as E51, which would skew your octane rating lower.

I wouldn’t bother doing the 89+93 blend though… 89 is running about $4.69/gallon and 93 is $4.99 in my area. Mixing the 2 equally (I used 10 gallons for easy math) comes out to $48.40, straight 93 is $49.90.

 

[slacktide_bitog]

Some flex fuel cars can take advantage of the higher octane, similar to how cars that recommend or require premium adjust for regular, but in reverse.

 

[blufeb95]

I’d definitely try blending e85 and 87, but you need to be careful because E85 isn’t always E85. It can be as low as E51, which would skew your octane rating lower.

At most of the stations in Indiana that carry E85 they have it listed on the pump that it contains 70% minimum

 

[wwillson]

Yesterday, I decided to try a half-tank of E85 mixed with the 93 that was in the tank. After 200 miles, the fuel economy seems to be comparable to straight 93, and the car is running fine.

The fuel economy will decrease, as there isn't as much energy in ethanol. Running straight E85 you'll get between 13% and 18% lower fuel economy.

 

[Skippy722]

At most of the stations in Indiana that carry E85 they have it listed on the pump that it contains 70% minimum

I’m not disputing it, but I’ve never seen it, all ours say 51% minimum or say 51%-83%. Most of Chicagoland being an EPA non-attainment area might have something to do with it.

 

[blufeb95]

I’m not disputing it, but I’ve never seen it, all ours say 51% minimum or say 51%-83%. Most of Chicagoland being an EPA non-attainment area might have something to do with it.

Maybe central Indiana happens to be far enough south we can get away with 70% minimum during the winter

 

[High Performance Lubricants]

Typically E-60 in IL

 

[skyactiv]

Fuel Economy of New Flex-fuel Vehicles

Fuel economy of the . 1984 to present Buyer's Guide to Fuel Efficient Cars and Trucks. Estimates of gas mileage, greenhouse gas emissions, safety ratings, and air pollution ratings for new and used cars and trucks.

www.fueleconomy.gov

 

[A_Harman]

The fuel economy will decrease, as there isn't as much energy in ethanol. Running straight E85 you'll get between 13% and 18% lower fuel economy.

That was what I was expecting, but that hasn't been the case so far. Ethanol has lower heat content, but the higher octane allows the engine to be tuned with more spark advance for higher efficiency. So far on 50/50, the fuel economy seems to be about equal, and I'm down ~15% on BTU's in the tank.

I expect fuel economy to drop on straight E85. But the lower price could still make it economical, if I don't mind filling up more often.

 

[Nick1994]

I'll be posting my E85 results within a week or two for my Jeep.

Spoiler alert: It GUZZLES E85. Never again for me.

 

[oldhp]

5 gals E85 + 15 gals 87 = 91.5 octane based on 105 octane for the E85. Maybe try that combo. www.bazellracefuels.com has a calculator.

 

[Skippy722]

I'll be posting my E85 results within a week or two for my Jeep.

Spoiler alert: It GUZZLES E85. Never again for me.

Same with our Grand Caravan. Went from 18-19mpg to 13-14.

 

[Cujet]

My F150‘s mpg drops from 12 to about 8mpg on E85. HP picks up some.

I don’t mind using E85 as I enjoy the addl power and I have a 36 gal tank. However the local price has been higher than regular for some time now.

 

[Rmay635703]

Our ethanol station pumps used to let you select a size to many different ethanol percentages

If I were the op I would run e30 or e50 as that guarantees premium + octane

Our stations used to have selections for either.

Something funny the op will find is that fuel economy does not go down linearly with more ethanol

My cars fall off a cliff somewhere above e50 but below that my fuel economy is better than expected.

E85 used to be a buck a gallon cheaper than even 87rug, depends how much of a price parity there is.

My guess is if it’s like around here and the comparison is between premium and e85 you are talking $1.50+ savings which is definitely worthwhile for an e30-e50 blend

Also worth noting ethanol fuel economy is massively effected by outside temperature
Below 60F and expect a 10% drop right off the bat.

 

[930.engineering]

After 200 miles, the fuel economy seems to be comparable to straight 93, and the car is running fine.

The fuel economy will decrease, as there isn't as much energy in ethanol. Running straight E85 you'll get between 13% and 18% lower fuel economy.

Exactly!
Regardless if you notice the decrease - it's still there.

That said, is it smart burning alcohol made from corn in cars while humans are
starving elsewhere and significant crop shortfalls in Ukraine are to expected?
.

 

[Rat407]

E85 is $3.54 here. Regular is $4.40. Cost per mile running E85 is the same using regular. To me the benefits of burning cleaner, higher octane and feels just better performance wise, E85 is worth it. Might not be for everyone but I like it as well as how the exhaust smells. Our Suburban loves it.

 

[A_Harman]

I did my first refill from the 50/50 E85/93 tankful, and got
(drum roll, please)
.
.
.
28.2 mpg. I went 403.3 miles, and burned 14.3 gallons of fuel. Fuel cost per mile: $4.60/ gallon divided by 28.2 miles/gallon = 16.3 cents per mile

The fuel economy of my previous tank of straight 93 octane was 30 mpg @ $5.00 per gallon --> 500/30= 16.7 cents per mile.
So I did save a little with the ethanol blend, but not enough to get excited about: .4 cents per mile x 400 miles = $1.60

The new tankful is 50/50 E85/87 octane. $4.20 for E85, $4.30 for 87, $4.25 average cost per gallon. Drove home on it, and it runs fine. Will report on fuel economy after I refill.

 

[Rmay635703]

Exactly!
Regardless if you notice the decrease - it's still there.

That said, is it smart burning alcohol made from corn in cars while humans are
starving elsewhere and significant crop shortfalls in Ukraine are to expected?
.

The corn planted for ethanol this year is a lost cause determined back in January, set in stone and not affected by any political contortions.

It’s not edible by humans and not healthy as animal feed
That is until you make ethanol, the 30% of the “corn” leftover from making ethanol is actually usable as a healthy mineral and protein loaded feed.

Ethanol production also offsets the energy needed to make dry ice and makes corn oil as a byproduct.

All the industrial cofactors made by ethanol production are in effect free byproducts that used to require a significant amounts of energy to manufacture but now are just a waste of making ethanol.

Elimination of ethanol production this year would not impact food production for people and could actually decrease the amount of protein loaded animal feed available.

I did my first refill from the 50/50 E85/93 tankful, and got
(drum roll, please)
.
.
.
28.2 mpg. I went 403.3 miles, and burned 14.3 gallons of fuel. Fuel cost per mile: $4.60/ gallon divided by 28.2 miles/gallon = 16.3 cents per mile

The fuel economy of my previous tank of straight 93 octane was 30 mpg @ $5.00 per gallon --> 500/30= 16.7 cents per mile.
So I did save a little with the ethanol blend, but not enough to get excited about: .4 cents per mile x 400 miles = $1.60

The new tankful is 50/50 E85/87 octane. $4.20 for E85, $4.30 for 87, $4.25 average cost per gallon. Drove home on it, and it runs fine. Will report on fuel economy after I refill.

Why would you mix 93 with e85?
87 has more btus and allows you to significantly cut the cost

Ideal mix for you would be e30-e40 mixed in rug for your 93octane


Anyway
Sucks that you overpay for e85

Around here
e85 is $3.75/gallon
Rug is $4.19
Premium $5.25

40%@$3.75+60%@$4.19=big savings over premium

 

[01rangerxl]

My F150‘s mpg drops from 12 to about 8mpg on E85. HP picks up some.

I don’t mind using E85 as I enjoy the addl power and I have a 36 gal tank. However the local price has been higher than regular for some time now.

My Ranger 3.0 is like this. Normal MPG is 15 MPG or so, with E85 it drops to about 10. There's definitely improved throttle response though and no pinging. The truck runs absolutely great on it, but at the cost of MPG. The price savings isn't "worth it," but E85 isn't really a thing here. I have to go way out of my way to buy it, so I only do it when it's convenient.