Summer mix fuel changeover

[brucepick]

I think that CT must have changed over to summer mix fuel on Apr. 15.

My mpg has been hovering just under 27 mpg since early March. This afternoon I tanked up and it came out at a hair under 30 mpg. Yes the afternoons have been warmer but a solid 10 % increase nearly overnight? I think the fuel changeover has occurred, at least in this state. Likely much of the Northeast is on the same schedule.

If you're watching for this in your mpg results - remember that you need to fill with the new stuff first, then you could notice results at the next fillup after that.

[RoadWarrior]

Not sure we've got it here yet, still smells wintery (Higher aromatic content, pungent enxhaust fumes etc)

[Hateful]

My mileage has gotten better recently but I thought it was just the warmer weather. The station I go to is always busy,so when it does change it should cycle out quickly.

[RoadWarrior]

Come to think of it, I might be on summer gas since I filled up this morning. I was having hard starting issues when the engine was hot the last couple of days, but it started up better today, despite being hotter.

[swng]

I am experiencing a slight improvement in fuel economy too, even with the AC operating occasionally. Summer mix is good!

[slurp812]

I thought the last tank was my good driving! :(

[maxc]

If you have fuel injection, in opinion, your engine should run better on winter fuel.
I'm running 3 month old gas right now. Had some stored with alittle stabliser. No heat soak starting problems.

Sometimes I notice after top the tank off. Restart heat soaked engine throttle responce is very good and lite. Probability because the charcoal canister is giveing the engine a good vaper shot.

I have a 50F offset on my CTS. No cold start problems.
It would an interesing test to see the effects of heat on summer/winter fuel at different temps and pressures. Observe fuel in a clear tube in "realtime".

[Danronian]

My MPG went up about 3 or 4 for my last fillup. My car idles a lot lower when it's warm out, so I do think that had a lot to do with it since it has been a lot warmer lately. But who knows!

[Improbcat]

My last couple of tanks have been impressively higher and I'm on task to get even higher with this tank. I loves me some summer blend gas.

[maxc]

With a few mods it would be better to run winter gas in summer. If you had a place to store it.