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So what do u guys think about ethanol in our gas. I was always thinking that it's not good & thus using only shell 91 which has no ethanol. But my friend told me that using sunoco 94 is the best gas for our cars even though it more octane then we need. What gas do u guys use?

rick89

yea i was told that shell 91 is better because it gives the car more power and it does not have wood alcohol in it like sunco. I also heard that sunco is only cleaner for the environment and you burn more gas quicker. Brian at independent tuning recommended that i use shell 91 v power.

awd-leo

Shell 91's all I've been using.

rick89

yea i think we should have a vote to see which gas is the most used on audis from the members in this forum. Unless they have already done it then yea.

1move

iTrader: (1)

Hey guys so here is a poll of what you fill up with at the pump!

plankspanker

I use Shell 91, but would use straight 94 if could get it here in Calgary. 94 ethanol mix = crap fuel economy! In BC Chevron sells straight 94.

1move

iTrader: (1)

Hey you should come out to our calgary audi club meet. Yeah 94 is the one i can get in calgary but its with ethanol

rusty_67

iTrader: (1)

Some chevrons (like the one here in penticton bc) have 92 instead of 91 (same price). not sure why, maybe they add more techron or something. But in any case that's what I use. I don't think I'd ever use an ethanol blend.

wanthema

another one of those gas threads.

94 ethanol octane all the way. more mileage, cleaner fuel and better for the engine =)

rusty_67

iTrader: (1)

We have beatin to death the subject of octane on this forum. Whether or not it affects your power. The bottom line is, the optimum octane level is the lowewst at which your car performs to its highest ability. If you use anything higher, it helps nothing and costs you more. This is TRUE, so please don't call me on it. How do you figure this out the optimum octane number? you'd have to know your combustion pressure, which is kind of hard to figure out on a turbo'd engine as combustion pressures change with the amount of boost. But you could probably figure it out if you knew the maximum boost that you run... but anyways enough on octane.

Ethanol vs. Gasoline.... It can be, has been, will always be able to be proven that the amount of energy produced (transformed to be scientifically correct) when burning Ethanol is less than the amount produced when burning the same amount (volume) of gasoline. Therefore you WILL get better gas mileage with the straight gasoline.

Now when gasoline comes in contact with water a suspension mixture is formed. So if there is any moisture in your gas tank, it will not mix. Ethanol on the otherhand absorbs water and when it does it significantly reduces the octane value. This can be a problem if you say switch to an ethanol blend after using gas for a long time and water has had time to accumulate in the bottom of the tank. That being said maybe its a good idea to fill up with a higher octane ethanol blend every once and a while to clean out your tank? But there are fuel conditioners for that too.

I'm gonna stick with gasoline for my Audi.