I'd rather get E10 than gas that's been in the tank for 6 months...

 

Something to keep in mind is that alcohol has around half the energy potential of gasoline. Thus you would have to expect a decrease in mileage with alcohol based fuels. In alcohol racing engines, the fuel system is about twice the size of a gasoline engine. However, with alcohol's high octane rating, you can greatly increase cylinder compression for volumetric efficiency.

 

Oh, and a read in regards to E85.

http://auto.howstuffworks.com/fuel-e...uel-works1.htm

 

Kind of timely I ran across this thread on fuels. Just yesterday I filled up my 09 2.2 with 93 octane just because.. The increase in power at the pedal was very noticeable. Now I'm wondering if the xtra octane will cause me any engine problems. I'm not always going to use premium but is it safe every now and then in a 2.2?

 

If your engine doesn't call for high test it won't cause any harm by using it..... typically it won't cause any benefit either.

 

Yes, it's completely fine to do so. I do, I like the cleaners they have in it (like Shell has, or so does Chevron.)

As far as benefits, that's really to each his own. People swear they get better mpgs with it, other say it's the same, some say worse. I've never had worse... Most times it's the same, but I've had before where I swear it gets better. It really may be a mind over matter thing. Now, I do know my truck runs better on it, but that's an old carb truck....

 

Well, your truck was built in '83, Regular gas was more than 87 octane back then so it's calling for better fuel. You should run a mid grade in that at least. On newer cars the cleaners and additives in high test can make a "regular" engine feel better if the injectors/etc. have become a little clogged.

 

I just wanted to chime in....

I have an '09 2.2 and use regular 87 octane on a daily basis. I am driving between 10,000 and 12,000 kilometers a month, 95% highway.

The injectors became fouled and I took it into the dealer under warranty. The dealer suggested I run premium (91 octane here) every 4th or 5th tank to keep the injectors clean, because of the additives in the premium fuel (techron / tactrol).

This was last fall, and since then, I have been running every 4th week with premium fuel. There is most definitely a difference in power between 87 and 91, however I havent seen any difference in mpg. The cost difference adds up as I am already spending $35/day or so on fuel with regular 87.

But in retrospect, running the premium 91 every 4th week keeps my mind at ease. I also run a bottle of ac delco fuel injector cleaner (techron) through the fuel system every couple of months. I am hoping to get 250,000 - 300,000+ kilometers out of this motor before I need to replace/rebuild it.

 

If you figure it out, it's only about 20 cents more per gallon, which is just over $3 per tank. Figure what's a bottle of injector cleaner, and it's cheaper to just buy it in the gas with premium. That's how I look at it. And I agree about the gas being different back then...

 

Premium in BC Canada averages around 13-15 cents a liter more than regular. With 30 liters being used a day, that equates out to about $78 - $90 a month difference for me between regular and premium. I know it gets confusing between liters and gallons. In the end, there is a bit of a price difference, this is why ive decided to stick with regular, with a bit of premium thrown in along with injector cleaner every couple of months.

btw we are taxed to death in BC, and with a harmonized sales tax being rolled out this year, the tax on fuel is going up another 6% if im correct. Death and Taxes