I was averaging 32.8 MPG and then I filled up at Circle K.

I usually use Shell gas, but this time I was on fumes and did not have a choice where to fill up.

I also was told by a few that they use Mogas, they might be wrong. As such I got 89 instead of 87 octane. Why? I don't know, I thought it might be less crappy because it is the intermediate and not clog my injectors. I am probably wrong.

What I am not wrong on is that the entire trip back home with this Circle K gas in my tank the MPG kept going down. I was not racing, not passing anyone, just cruising 65mph home the whole 30 miles.

When I got home it went from 32.8 MPG to 32.1 MPG!

I only put 4 gallons of that crap in on Thursday, and after I filled it back up with Shell gas, the MPG went up to 32.5 on the way to work. I am betting the ride home will land me 32.7 at least. Tomorrow it will be back to 32.8MPG.

My 2.2 hates Circle K gas... anyone with a similar experience?

Oh yes, and by the way, I have used 89 and 91 octane at Shell and it did not affect the MPG much.

 

makes sense, most shell gasolines (at least around here) dont contain ethanol. ethanol in the gas reduces mpgs, but its also cheaper than 100% gasoline. also, using a higher octane does not increase mpgs it just is a much cleaner burn and will help ur injectors and plugs and stuff last longer. i believe our cars are tuned for 89, so thats wat i always use and i get pretty good mpgs for an auto.

 

So that is it, Ethanol.

Thank you for the info.

My brother keeps filling his car with Circle K gas mostly and has the sedan 2.2 LT.
His mileage was at 26.5 MPG this weekend. I was thinking, come on I know he is a lead foot, but that level MPG is ludicrously low for the 2.2 of any flavor.

 

i actually get around 27.5, but im also a pizza delivery driver, so ALL my miles are in the city at low speeds, lol. yea its the ethanol, cuz even though it doesnt get u as good of mileage its also usually .5-.10 cheaper than 100% gasoline.

 

i get 27 mpg average with BP 93 octane, and yes i am tuned for it.

 

Thats not enough IMo to call it bad gas. To call it bad you should measure the consumption for hte same one way trip with both. Road imperfections,wind, other thing could probably account for this, in my mind at least. Google circle k gas I will!

I can drive my balt to get under 13mpg btw

 

No CircleKs by me but i can tell you that our local convenience chain (Wawa) gas will absolutely hurt your fuel mileage as compared to Shell or other top tier fuel. 2mpg difference isnt uncommon at all.

 

Interesting (there's no interesting smiley face )

 

Well, I filled up the entire tank and not just a couple gallons to mix with the Circle K gas at the Shell station 89 octane yesterday morning.
The drive to, and from work plus todays to work has made the MPG even out at 32.5MPG.

It keeps dropping to 32.4 as soon as I get off the freeway.

Doesn't sound like much, but, I was at 32.8 and it kept increasing when I used Shell 87 octane. Like I said, it dropped like a rock once I used the Circle K gas with ethanol.

I wonder if at 89 octane, for my driving, that is the tops it will go?

I will give it a couple more days, but literally with the 87 Shell it was going up .1 each day.
My old MPG max was 31.1 and when it kept climbing since I work further from home, it passed that old max and probably would have passed 32.8MPG.

I guess it is back to 87 for my LS, which is what I used 99% of the time anyways.
So far it seems the car likes 87 the best.