Curious about something,

My complimentary tank of gas two weeks ago was filled with BP 87 (now Amoco I guess). When I filled up a few days ago with Citgo 87, I noticed immediately (within 1-2 miles) that my car drives differently especially the way the auto trans shifts.... a little rougher shifts sometimes with the exact same footing or even a delayed shift or two on the same exact streets I always drive.

Can different brands make that cars computer adjust for timing and shift sequences? Or is it possible that Citgo or BP were not true 87 octane and therefore either one was higher or lower than a true 87? Because everything was smooth as glass with that first tank of BP (87?).........

What do you all think?

I really doubt that different gas will make the Scion run any differently...

Especially the shifting points... that's the tranny and shouldn't be affected by the gas you use... are you sure it's not just in your head?

The only thing that would affect the way it drives is if the gas is not pure, then it might not run as smoothly but it wouldn't affect the transmission...

I saw something on Discovery channel or ? a little while back. Gas is all pretty much the same(all formulated for specific markets due to emissions/pollution guidelines/requirements) Could have been a bad batch or something, but not neccesarily due to brand.

With that said, Quicktrip's gas is the best because they have crushed ice for the fountain drinks.

My SAAB (RIP) loved Shell gas. I have no idea why, but
it just ran more peppy on it.

You are *never* supposed to fill up if you see the "filler
truck" at the station. When that tanker is dumping all that
fuel into the station, it will dredge up any sediment in the
tanks.

Depending on the age of the station, and what laws apply
to your area, there may also be some moisture in those
tanks.

I try to keep track of when new Shell stations are being
built, so I don't have to worry about those issues.

I can't imagine though, how this would effect shifting.

It seems to me, the only thing that makes a huge difference, is the grade of the gas. The lower the grade, the worse your car might (MIGHT) perform. My Beetle wants a high grade, I have noticed, or it knocks a bit. My Box, seems to like the mid grade.

Here in the SOUTH, you want to avoid gas stations with puddles, since the water will settle into the big tanks over time, which will weaken the fuel. So I was told by a station owner.

I always try to avoid the cheaper gas, as in, the stuff that comes from the cheap stations. You never know what they will put in that stuff.