IIRC? what is that acronym for

 

If I remember correctly

 

Hmmm... interesting comments. If the winter blend is available that early, then my thought on the air temp may not be it and could be the winter blend. Back to the drawing board!

 

I believe the winter blend gas will react better the colder and denser the air gets.

 

All turbo'd engines prefer cold dense air.......

Yes winter blends start being made on September 15th doesn't mean your station or all stations are switched over. Especially with higher octane blends that have less sales. Try another station if you frequent the same one. Try a 93 octane or mix 89 and 91.....anything to see if it's fuel. Vibrations are tricky and never just accept they all do it crap. Mine doesn't do it.

-The national average price for unleaded gasoline is expected to keep moving lower as we head into fall barring any unexpected disruptions in supply or spikes in the price of crude oil. Pump prices typically decline during this time of year due to lower driving demand after the busy summer driving season has concluded and the changeover from summer-blend to a cheaper-to-produce winter-blend gasoline, which takes place in many parts of the country starting on September 15.

The difference between summer- and winter-blend gasoline involves the Reid Vapor Pressure (RVP) of the fuel. RVP is a measure of how easily the fuel evaporates at a given temperature. The more volatile a gasoline (higher RVP), the easier it evaporates.-

Winter-blend fuel has a higher RVP because the fuel must be able to evaporate at low temperatures for the engine to operate properly, especially when the engine is cold. If the RVP is too low on a frigid day, the vehicle will be hard to start and once started, will run rough.

 

Thinking this through, let me know if this makes sense. If the local stations have not switched to winter blend, and we have some cold days, the car may run rougher since the RVP is too low in a summer blend? Am I thinking correctly? That would certainly explain why its worse at present...

 

From what I've read the winter blend was allowed by the government so that gas companies can make a lower quality gas cause during winter months gas evaporates less.

You would get ever better gas mileage and better performance during the cold weather season if they sold summer blend gas. But it's all about money.

 

Makes sense , but still the engine management should adapt to the fuel. How bad is this vibration does the wheel vibrate while idling? Hood open is the engine vibrating? Also remember the cold dense air affects the turbo setup.
So many variables..........

 

I sense vibration when the car is stopped uphill at a light, no brake hold, just foot on the brake. I suspect it's due to the computer compensating (slightly raising RPM) for uphill start roll back when the brakes are released.

 

I sense a similar vibration with my new A4 on idle and in addition, during low rpm acceleration in a higher gear.

 

New '17 with 300 miles and there is definitely a small vibration when stopped at a stop light and even more so when I take my foot off the gas to accelerate from a stop. Nothing to obnoxious, & no where close to the vibration our Kia Soul has.... unfortunately, I think it's the nature of the beast with a 4 banger under the hood....

 

People, this is a real issue! Just came back from my 10k service and they fixed the problem per a TSB ( technical Service bulletin ) The word "Problem" was a problem and now its fixed.
work sheet reads: Reprogram PCM per service bulletin

 

can you post a pic of your service with the TSB info on it?

 

Sorry, I was looking for a number also but service report does not have it. I also have Atomic Silver!

 

Any chance you can call the dealership for the information? It would really help the rest of us.