Tonight I went on a joy ride and happened to find a gas station that sells premium gas without ethanol. I read somewhere that older engines don’t really do very well with ethanol, so I put in about 8 gallons. I figured, what could it hurt? I wanted to see if it would wake the old girl up a little bit.

And dare I say it, the car actually felt faster. Is it all in my head? In my experience, I’ve found that cars tend to be peppier on a full tank of gas. Or was it the fact that half of my gas tank was filled with 100% premium unleaded gasoline? If it was the latter, is it too much of a shock to the engine to switch to straight up gasoline, or am I overhyping it too much and it’s either not worth the extra money or actually harmful to the engine?

Then after coming home and doing a little research, it turns out that the “premium” gas without ethanol may actually carry an octane rating of 87 and not 91 or 93. I’ll be reaching out the station for confirmation. Until I find out, assuming that’s true, what’s the lesser of the two evils: 87 octane without ethanol or 93 octane with ethanol?

 

With only 2/3 the energy of gasoline, ethanol costs more per mile.
http://zfacts.com/p/436.html
Plus the ethanol degrades any components in your fuel system not designed for it.

 

It is very simple as to why you experience what "felt" like the car being faster!

1. Even at 10% blend with gasoline, Ethanol reduces the burning power of gasoline when compared to pure gasoline.
2. To further aggravate the reduction in power, Ethanol, even at 10%, is hygroscopic which means it bonds with moisture from the air every time you fill up the tank which is why over time you have water accumulation in your gas tank!
3. To further aggravate the reduction in power, Ethanol goes through phase separation after sitting for a few months. You are not supposed to run your car frequently on an empty tank but filling up and leaving some gas in the tank can result in old Ethanol that gunks up and this works at deteriorating the fuel quality along with the entire fuel system of the car! This is why you need to use fuel additives to clean out and stabilize the fuel every so often!

I am sure the oil companies have nice chemical cocktails to try to squeeze out better performance from their Ethanol blended gasoline but I find that pure gasoline is so forgiving and requires less maintenance than ethanol blended fuel, which is why I am using it in my car, for now. The ultimate in alternative fuel is 102 octane Iso-Butanol developed by a company called GEVO. Unlike Ethanol, Butanol can be mixed with gasoline up to 100% and can be used as a stand-alone replacement for gasoline and the best part is, it is non-hygroscopic so it won't draw in water moisture and even better, it doesn't gunk up like Ethanol and it doesn't go through phase separation. Despite having a closer BTU level to gasoline and higher than Ethanol, you still marginally use more than gasoline BUT with higher engine compression you can recoup this loss! I do plan on testing this fuel in the future too, when I have the money to invest in it.

 

If you dont like the high prices of E0 gas, you could just buy premium in a 5 gallon jug, dump in water, shake shake shake, let sit overnight and drain the ethanol/water mix and youll end up with 4.5 gallons or E0. Minus a couple octane since the ethanol apparently acts as an octane booster. So overnight, I go from 5 gallons of E10 93 octane to 4.5 gallons E0 90 octane.

https://www.jegs.com/i/JEGS-Performa...80210/10002/-1
https://www.jegs.com/i/JEGS-Performa...80218/10002/-1

I ran it first in my lawmower, which was fine. Then my daily 2014 mazda 6 which had no problem. Then the truck, then the camaro. I watched the fuel trims on the mazda and camaro, and the camaro ran a little richer in the long term. Dave at gearhead EFI said that would be expected now that 1 gallon of straight gas has more energy than 1 gallon of E10, so the computer would have to be pulling back a little fuel in order to get good AFR.

 

Ethanol sucks...

 

Non-ethonal gas for these cars are leaps and bounds better than any premium gas you can get. For all the reason's Pheniox 97 states (which is spot on for Ethonal in gas)and what you felt when you took your cruise there should be no question on what fuel to use. I have been on REC 90 for 8 or so months now and not only did I get the peep back in the car it cured a common problem of hot starts. Hell, it even improved my cold starts also. I will never go back to ethanol fuel for my Z !

 

Guys, almost everything written here is incorrect information as far as power and acceleration of the car is concerned. 10% ethonal will not hurt anything except it may cause a slight 5% reduction in fuel economy. As far as power is concerned the higher octane of the ethonal is a bonus and ethonal itself is a bonus for power, before people start killing me for this consider this. Our cars are designed from the factory to run hot so the added octane will allow you to run additional timing before it is pulled due to detonation, in other words run the 93 octane fuel before 87 octane fuel. Next our cars are also very rich at WOT from the factory so the 5% leaning of the AFR at WOT helps make more power. Takes it from an AFR of high 11's to around 12.5 which is better for power. Additionally at cruise the O2 sensor takes over to keep the AFR at stoich so the car still runs fine just uses slightly more fuel. Lastly you can make more power with ethonal fuel when compared to gasoline when both are tuned for best power, sure you will use more fuel with the ethonal but at the correct AFR for each fuel more power is produced with ethonal fuel. Since are cars are already too rich from the factory and ethonal leans it out you get the additional knock resistance of the ethonal and the better AFR for additional power.

I have done back to back testing on the chassis dyno with my 406 Firebird and picked up around 25 HP by running E85 fuel tuned correctly vs 93 octane fuel tuned correctly. This is in a high HP 406 with 11:1 compression.

Do not fear ethonal 93 octane fuel

 

That being said, modern fuels WILL degrade any older rubber compounds that it passes through. The fuel will also spoil much faster than ethanol free fuels and it will also introduce additional water to the fuel system\fuel storage.

 

That is what I hear but I can only tell you that all cars after 1986 were designed to resistant to 10% ethonal in the fuel, so they should be OK.

I have a 1986 vette, 1988 firebird and a 1973 lawn mower and they all work fine on Ethonal fuel. Just my experience. To me it seems like ethonal fuel is blamed for most issues when it is really poor maintenance.

 

All I can say is the "seat of my ****" dyno on my stock 91 reads about an 8%-11% gain...I know these dyno's aren't that accurate especially the age of this one!

 

My 97 Express vans Vortec 350 had good gains in horsepower and torque running E85 after I tuned it running a factory GM flex fuel 5.3 operating system in the PCM.

My factory flex fuel Nissan Titan had a 3 tenths of a second ET reduction in the 1/8 mile simply refueling with E85.

 

I never run ethanol blend in my car because I don't daily drive it and ethanol will gum up if it sits in a system too long. Tough on rubber and such also. You don't believe it put some in a clear can and leave it a few months. In a daily driven vehicle it seems to do ok.

 

It draws moisture into the fuel system and produces a nasty yellow varnish that cloggs things up. It also decreases fuel mileage.
If your car is fuel injected and driven regularly, there should be no problems, but with carbureted cars that sit parked over the winter, it absolutely sucks. Gunks up the carb, and on hot days, boils in the fuel bowls, causing flooding which makes the engine hard to start.
There is no legitimate reason for using ethanol in regular gasoline except to subsidize the agricultural industry since ethanol made of corn. It DOES NOT help the environment one bit..