E85 vs E10(gas+10%ehtanol)

[redpoint5]

Originally Posted by brandonppr

I wish they would make the cars to run on E85 only, but I guess there are not enough pumps. If they could run E85 only I think they could do better cost wise than flex fuel or gas cars.

I wish "they" would stop mandating the wasteful practice of putting good ethanol into a fuel tank, but I guess there aren't enough alcoholics to drink it all. If they ran E0 only, the cost of everything would be lower.

[Allch Chcar]

As long as it is illegal for the EPA to test with anything but test grade Gasoline we won't see legitimate EPA scores for E85.

GM is advertising almost the same MPG in their new Regal compared to 15% loss for old FFVs. And I have heard that of some people getting 15% less...

Originally Posted by trooper Tdiesel

an engine made for 93 octane and e85 would be a much better set up

making one that runs on 87 and E85 makes no real since. it runs like poooo on E85 in regards to MPGs

ive thought about it but haven't, since i have diesel and beat the gas by-far.

low compression say around 8 to 1 with boost. that would let you run 89 or 93 octane when needed.
or high compression like 11 to 1 mabe a little more, and just barely run on 89 or 93 with out pinging.

10:1 is more like it today with DI.

It's a great idea though, I believe BMW did a study and found that Premium was worth 3% more power and MPG hence why they build for Premium. With Gas over $3 it would be worth it for more manufacturers to start doing that. And then they would do better on E50 or other midblends, making a good compromise for a FFV.

I wish Ford would get behind that!

Originally Posted by redpoint5

I wish "they" would stop mandating the wasteful practice of putting good ethanol into a fuel tank, but I guess there aren't enough alcoholics to drink it all. If they ran E0 only, the cost of everything would be lower.

There is actually a state by state exemption. Iowa for example offers Gasoline next to Gasohol(E10) according to some of the guys in Iowa. Probably something to look into and push. This mandating Ethanol is pissing people off more than anything. I say at least make it optional!

[rmay635703]

Originally Posted by trooper Tdiesel

an engine made for 93 octane and e85 would be a much better set up

making one that runs on 87 and E85 makes no real since. it runs like poooo on E85 in regards to MPGs

ive thought about it but haven't, since i have diesel and beat the gas by-far.
.

Actually many modern cars have the same compression ratio on non-performance setups that older cars did that required Hi-test to operate.

Supposedly GDI gasoline direct injection was supposed to allow us to run the higher compression rations needed by ethanol while still being able to run equally efficient on gasoline, interesting how that hasn't panned out.

[Allch Chcar]

Originally Posted by rmay635703

Actually many modern cars have the same compression ratio on non-performance setups that older cars did that required Hi-test to operate.

Supposedly GDI gasoline direct injection was supposed to allow us to run the higher compression rations needed by ethanol while still being able to run equally efficient on gasoline, interesting how that hasn't panned out.

The Regal is the first car that is GDI and FFV, but I haven't seen MPG for it yet. The Focus FFV is another possible example but it's not available in FFV yet. Infact I believe that was just a rumor... dangit Ford!

I found a couple guys running E85 in their new Buick turboes. They're getting pretty poor gas mileage on premium though. http://www.buickforums.com/forums/sh...ad.php?t=21293

[roosterk0031]

I've played with some blends earlier this year with the Stratus, March thru June. Here's a piece of my data, these tanks were all back to back. Most recent first, so some of the upward gain is also changing driving habits.


35.13 E0 mileage
30.06 E44 mileage
33.57 E24 mileage
32.28 E16 mileage
33.05 E10 mileage
30.73 E21 mileage

"Note the above data won't compare to new data"

I've just refilled after restarting my E blend experiments, first tank of E32 gave 32.02 mpg, today I put in 9 gallons of E10 and then finished fill with E85 to a E25 blend.

Also my most recent 3 tank E10 average was 35.58. most recent E0 3 tank was 36.09.

So roughly E32 gives 89% the mileage of E0, E10 give about 98.6% of E0, and E32 give about 90% of E10 mileage. Cost per mile is within 1/10 of a cent per mile.

I'm actually surprized at the E32 mileage, just a single tank but I squeezed in as much E85 in as I could both times and wasted a little tonight.

Temps also going down fast, 30-40f mornings going into 20's for this next tank. Car definelty likes hot weather best.

Speaking of GDI + turbo, nissan Juke has my interest, it requires premium so E15-20 blend would be plenty high octane wise, trying to get one of my brother to buy one. Awd rated at 30 mpg hwy I know I could get to 35 or better.

Taking the Impala on a almost 1000 mile road trip this weekend, I'll fill it up with E85 tomorrow night and collect some data for it over the weekend.

[PaleMelanesian]

E % | MPG |theoretical mpg|Error
00% |35.1 | 35.1 | 0%
44% |30.1 | 30.0 | 0%
27% |33.6 | 32.0 | -5%
16% |32.3 | 33.3 | 3%
10% |33.1 | 34.0 | 3%
21% |30.7 | 32.7 | 6%

Theoretical is calculated using ethanol's 67% BTU content compared to pure gas.

For real-world driving in varying conditions, it looks amazingly close.

[roosterk0031]

I was curious to check it that way just hadn't got to it yet.

Per the source I linked back a page they said it's actually closer to 28% less energy by volume, the 32% I found initially is by weight. Here a clip of their relative energy comparision by volume per that source.

E0 = 1
E10 = .964
E20 = .927
E50 = .825
E85 = .716
E100 = .657

Filling in the gaps I got

E25 = .910
E30 = .893
E35 = .876
E40 = .859
E45 = .842

Using my most recent E0 base of 36.09 and energy by gallon I should get.
E10 = 34.79 mpg but got 3 tank average of 35.58) (2% high)
E32(0.886) = 31.98 mpg (but got 1 tank at 32.02 ) (0.1% high)
E25 = 32.84 mpg (1 tank of 32.05) (2.4% low)
E32 =

[roosterk0031]

Switching to my wifes Impala and her driving.

E10 3 tank average is 28.62 converting that to E0, it should get 29.69. Calculated E85 mileage is 21.26, most recent 3 tank E85 is 24.5 mpg, (15% higher than it should be).

This data or I should say my wifes driving is erratic & unpredictable at best. Her work commute is 4 miles of 55 mph, but somehow goes thru a tank every 2 weeks or less.

[ksa8907]

Id like to revive this thread. I've had octane knock with moderate throttle and revs anywhere over 3000 rpm for the last 6 years. Finally realized it was octane knock after a hot day with my new grill block, It sounded horrid. To remedy the situation I'm going to test e20 to e30 blends.

Currently have 1 gallon of e85 mixed with 16 gallons of 87 octane for e14.5 and 88octane. After 250 miles I do notice the car has more power below 3000 rpm, but when the car gets hot I still get knock and i lose all the power i gained. Ill be refilling in the next few days and mixing to e25 and about 90.5 octane.

All fuel here is e10.

3.2 v6 24valve sohc, 9.5:1 compression.

[redpoint5]

Originally Posted by ksa8907

Id like to revive this thread. I've had octane knock with moderate throttle and revs anywhere over 3000 rpm for the last 6 years. Finally realized it was octane knock after a hot day with my new grill block, It sounded horrid. To remedy the situation I'm going to test e20 to e30 blends.

Currently have 1 gallon of e85 mixed with 16 gallons of 87 octane for e14.5 and 88octane. After 250 miles I do notice the car has more power below 3000 rpm, but when the car gets hot I still get knock and i lose all the power i gained. Ill be refilling in the next few days and mixing to e25 and about 90.5 octane.

All fuel here is e10.

3.2 v6 24valve sohc, 9.5:1 compression.

What octane does your owners manual call for? It sounds like you have another issue that needs to be addressed that is causing the knocking. The compression ratio you list and engine size doesn't seem like something that would require high octane. Shouldn't warmer intake temperatures decrease knocking due to lower density, or do the warmer temps play a larger factor?