JBurer

http://www.autoblog.com/2010/10/13/e...r-new-ish-car/

Interested in hearing opinions related to the new E15 gasoline blend becoming available. Reading that it's approved only for 2007 and newer vehicles makes me wonder what the tuning implications will be for modified cars designed to run on current premium fuels.

This won't impact most of us - but for that guy who was just barely getting away with running his RX-7 lean on existing fuels (or a modified car tuned on the ragged edge), I think it could be a problem.

I'm making a couple assumptions:
1. One of the reasons 2007 and newer cars are approved is due to more advanced knock control and, perhaps, compensation for the introduction of the 10% ethanol blend around that time.

2. Ethanol, having a lower per-volume energy content, requires more of it to keep the mixture stable.... so replacing 5% volume of 93 octane gasoline with ethanol is similar to reducing the amount of fuel delivered by a small amount (2%?)

Curious your thoughts!

$lacker

iTrader: (9)

Will this effect people in Canada?

Will American gas stations now have a set of pumps for new cars and a separate pump for old cars? How do you sell gas that is only acceptable for cars 3 years old or newer?

cptpain

iTrader: (1)

Because it mentioned that there is a possibility of stations carrying 5 fuels..

87-89-93/91/92-E10-E85

E85 pumps in my area are stand alone pumps separated from the regular octane gasoline and diesel pumps.

theadrock13

Its horrible.
Let that be a lesson to those of you who don't vote, or who vote for Leftists.
If you can get racing gas nearby, I'd put in a few gallons per fill up.

I'm curious what others' thoughts are on this choice in a TT FD: I can get ethanol-free gas at 89 oct near me. Whats a better choice, 93 oct with 15% (or more) ethanol, or 89 oct pure hydrocarbons?

natothegreato

iTrader: (1)

well guys i kinda hate to bring this back from the dead but there are a few things you should know about ethanol if you dont already. I am a GM factory trained technician and while other auto anufacturers may obviously be different this is what my instructors and several engineers at GM told me about e85 compared to regular gas... there are 2 main differences besides the fact that one can be made mostly from corn. The first is that e85 has an octane level of about 105 and the 2nd, which i thought was very interesting, is that when you burn e85 you need to use more because it brings along some of its own oxygen. thats it. the only difference in the "e85" marked vehicles and normal ones are in the ecu and the seals used in the fuel pumps and injectors because the alcohol tends to eat away at the normal seals. there have been several cars pulled into my stall that were running great and the owner said they thought the car was running better than ever, but the check engine light was on... well the ecu couldnt compensate for the extra oxygen in the fuel and the o2 sensor was setting a lean code. these cars were not misfiring and nothing on them broke, granted only one had a whole tank ran through it. anyways take that for what its worth, i hope they do add more alcohol to gas, maybe the price will go back down for a while. personally im guna be making the switch to e85 pretty darn soon so the price of normal gas wont really concern me. lol.

natothegreato

iTrader: (1)

o. almost forgot... non e85 cars (made by GM anyways) are able to handle up to 15% ethanol anyways, according to our service manual so i dont see what the big deal is.

NoPis10

iTrader: (29)

YES...

E85 is cheaper in price but you use MORE of it to produce the same amount of energy that 93 requires thus you use more than you would of 93. This in turn would negate the cost savings that everyone is concerned about.

arghx

iTrader: (3)

just keep in mind that E85 is subsidized by the government and if the political winds change it will become more expensive

natothegreato

iTrader: (1)

its not that much more tho... only enough to compensate for the added oxygen. idk exactly how much that is but on e85 vehicles there is a 1 or 2 mpg difference. thats not all that much imo.

cptpain

iTrader: (1)

E85 for me is $2.08

93 is $3.30.

I can deal with a little less fuel economy for cheaper fuel with a higher octane, equivalent to gasoline

MAXX65

iTrader: (2)

So who going to be the ginny pig and try it in their 7? I want to know what happens, but I don't what the negitive reprocussion to happen to me :-)

Narfle

iTrader: (16)

Are we talking about e85 or e15?

e15: ****
e85: awesome

The problem with e15 is that if you car is designed for gas(read: not flex fuel) it'll **** it up.

scotty305

iTrader: (2)

E85 isn't new, there is plenty of info out there if you search for it. The chemistry involved requires about 30% more ethanol vs gasoline for the same power levels. It has some nice properties that tend to result in increased power, especially on turbocharged engines. It can help with non-turbo cars, too: a friend switched his autocross Miata to E85 during a dyno session in order to compare against pump gas... it gained at least 5 HP across the entire powerband, which wasn't too bad considering the class rules don't allow many engine modifications.

The consensus I've heard is you won't save any money compared to pump fuel, but may be able to achieve race-gas power levels for less money. Will decrease fuel mileage significantly, is much less available than gasoline, and tends to contaminate the engine oil more quickly than gas.

NoPis10

iTrader: (29)

Thanks.... You said everything I wanted to say...

natothegreato

iTrader: (1)

thank you... and i cant even get 91, let alone 93. but theres an e85 pump bout 10mins from here.

theadrock13

According to Cam at Pettit Racing, you want to entirely avoid using ethanol gas in your rotary if possible. Since thats usually unavoidable because of the jackhole politicians taking away our freedom to choose, he suggests to add a few gallons of AvGas or Racing Gas per tank to help offset the damage from the corn fuel. (And don't forget to add premix with every tank. It works.)

The reason corn is so bad for rotaries (if I understood correctly) is that it attracts water/humidity very quickly -- like a sponge -- and its the water in the tank that will damage your engine.

Maybe piston engine GMs can cope with corn, but my 350HP TT FD isn't worth taking chances on that crappy fake gas.




P.S. It takes more energy to make ethanol from grain than the combustion of ethanol produces... so don't fall for the scam. Read for yourself.

arghx

iTrader: (3)

don't succumb to internet forum fear-mongering. E10 isn't going to cause any problems with your car if it was put together correctly, maintained properly, and tuned appropriately. There are many many people on here who have had zero problems with E10, myself included.

seriously. just drive it and check the oil. quick freaking out. There is already an E85 subforum on rx7club btw.

bajaman

Yeah...my new Ford truck is flex-fuel but with the significant reduction in miles per gallon compared to dino ****, the only way it makes sense to run it is if it only cost about $1.85 or so....and frack....it is ten cents HIGHER than gasoline in my area!

Someday I'll put a tank in, just for grins....wonder what the exhaust smells like?

natothegreato

iTrader: (1)

it does attract water thats y you nolonger need to use heet. however i have put over 30,000 miles on mine running nothing but e10 and it hasnt done any damage at all. i get about 25 mpg last time i checked. i honestly dont see what all the fuss is about.

Aeka GSR

iTrader: (4)

edit.