Always run the 89oct in my truck. Last nite stoped at the Gas station to fill up and was looking at the prices. So here is what I did and wanted to see what you guys think.( will this help MPG or not)

89Oct with 10% ethanol @ 4.19 gl
91Oct with 0% ethanol @4.39 gl

I added a 50/50 mix of 89 and 91 to the tank.

Now with the 91 not having any ethanol when mixed 50/50 with 89 @ 10% ethanol my thinking is that I now have 90 octane with 5% ethanol.

I say that I should get better MPG because of the lower % of ethanol.

So am I way out in left field or do you Guys agree??

 

I mean I guess technically that should be true. I wouldn't know because I'm not a fan of mixing gas grades. I just pay the extra 5 bucks and fill up with straight 93 and then use StarTron to get rid of the ethanol. Just buy StarTron and that will get rid of the ethanol for you if that's what you're after

 

All gasoline is blended. I've been mixing 87 and 93 (at Costco) in both Hemis for years. It works out to 7-10 cents/gallon less than straight 89. I suspect the small change in the percentage of ethanol will have little to no effect either way.

 

Thats 5 bucks extra for the non ethanol 91 per tank. It will definitely get you better mpg. Just fill it with the 91 non ethanol and quit playing chemist lol. 5 bucks a tank won't kill you I'm sure, especially if you get further on it. I wish I could get non ethanol fuel here.

 

What about if your someone like me that only has 87, 89, and 93?

Last time I got 89 locally the truck didn't seem to run that great. I dont know if if it was watered down or not the greatest batch or what.

But the next time I did half 89, half 93 for a 91 mix and it seems to run great on that and I guess would help protect if the batch wasn't the greatest.

 

I'm sure it's not bad to mix it and it probably does come out cheaper but personally it's not worth my time to swipe, fill and then swipe and fill again. Call me crazy but that's just too much work lol

 

I'm pretty sure here we have 87, 89, and 91. The stations only bring in, 87 and 91. 89 is blended in the pump. That's what I've been told.

 

I dont do it to be cheaper, I honestly do it just in case the gas isn't a great mix.

Id hate to have problems because the 89 I got was watered down or the mix was ****ty. Atleast this way if it is a little bit down, its still fine.

Im sure if you went around and tested gas stations, you'd find alot that sometimes are under what they are supposed to be.

 

We have no 91 here, either. My Hemis have not had any digestive issues whether we use 89 or a 50-50 mix of 87 and 93.

 

That's why I use StarTron. It gets rid of the nasty crap in gas and makes it a straight gas mixture, no ethanol or anything. Also you may be getting bad gas depending on when you go. If you go to a gas station right after it's tanks have been refilled then there's a bunch of junk that's been stirred around and will get into your tank which could cause poor performance