Quick Concern re: Reglar gas in 4.2. Input wanted
 

So Atlanta has decided to run out of gas. Morons are in a panic and even though they have almost full tanks, they keep topping off so that they do not run out. It should subside in a few days but whatever. Anyway, there is no premium, very limited places that have mid grade and some regular. My wife has my car for a few days while I am having hers worked on. She, like many decided that with 5 gallons left she was sure to run out on the road and despite having enough to get her through her daily routine for the next 3 days, she goes to the first station she sees and proceeds to put half a tank of regular in my A6, 4.2. Then the ever so helpful ding dong working there suggests she put some crap octane booster in, which she does.

Q: will this result in divorce, or will this result in some rough riding in the car for a few days and be righted next time I fill with premium? Thanks.

P.S. it ran ok on mid grade once but it was only a few gallons that time.

Have no fear. Your car should be fine. But i would strongly suggest against a repeat. That octane booster should be burned up too by the time you fill 'er up. I have personally noticed a significant difference in engine performance with regular gas (87 octane) vs. premium (93 octane). AAA, the Feds, and sometimes the dealership will tell you that its okay to use 87 octane. Modern engines are all capable of adjusting to the grade of fuel unlike older vehicles. Dont beleive all that bullcrap. Long term, your engine will suffer and you're looking at a major problem down the line. So, always take the high road and load nothing but 93 or higher octane.

thanks for taking the time. That is what I assumed, but was glad to be reassured.