tell me if this makes any sense

[grandmacpubah]

My dashhawk is usually on fuel trims...it's always in my car and on.

My trims are pretty darn stable and look good.

I've been using brand Y gas for awhile but the other day I used brand X gas and all of sudden my trims were like 5% more negative all the time...at idle I was around -4% and at throttle tip in -7% through -10%...just cruising.

I was like wth went crazy with my fuel trims? So I coincidentally filled up with brand y again and all of a sudden they are back to normal...does that make any sense? Is it possible for different brands of fuel to affect fuel trims?

[GRRRR8]

The amount of alcohol in the fuel is what causes that.

[grandmacpubah]

The amount of alcohol in the fuel is what causes that.

no kidding..interesting...so by looking at the trims I would know which one was using more/less ethanol?

[Steve]

Post which brands they were - Tired of the crappy gas around here!
so 'Y' would be better?
(wouldn't it be logical to start with X, and then mention Y? ) haha

[grandmacpubah]

Post which brands they were - Tired of the crappy gas around here!
so 'Y' would be better?
(wouldn't it be logical to start with X, and then mention Y? ) haha

Well I wasn't sure if that was ok lol

I usually fill up with shell or 76 (brand y) I filled up with chevron (brand x) because it is closer to my house.

Isn't one of them advertising nitrogen in the gas?

*edit for Steve...hey it's been a long week of golf! I played 36 holes yesterday!! I can promise no quality brain activity here*

[Devilish34]

Post which brands they were - Tired of the crappy gas around here!
so 'Y' would be better?
(wouldn't it be logical to start with X, and then mention Y? ) haha

No Z

[Steve]

Golf? lucky you!

I usually get 76... seems to be alright... sometimes chevron but very rarely, and never Shell or Arco (and that's about it for gas stations around)

[grandmacpubah]

I just looked online and it's shell with nitrogen in it...and chevron has techron (wth?) I don't remember 76 gas saying anything about additives.

Am I the only one who thinks that's really interesting that different gas does that to your fuel trims?

I love this forum.

[grandmacpubah]

from my casual reading online so far...it seems that the lower (negative) fuel trim numbers would actually indicate less alcohol in the fuel mixture...so maybe the Chevron is better?

I've been reading about WRX people who have run E85 and have to raise their fuel trims to the max to get it to work, so it seems more alcohol requires a higher fuel trim.

I'm thinking Charlie better step in pretty soon before I start spreading bad info lol

[GRRRR8]

Fuel is very tricky. You have summer blends (burns slower), winter blends (burns faster). This factor causes some drivability issues in cars when spring comes. From my findings Shell has the highest ethanol content. This varies state to state as certain areas mandate X amount of it in the fuels. I only use Exxon 93. When I was in Georgia I only used BP 93.