2008 S Cayenne, was getting close to 550-600 km to a tank, then one day after arriving home I heard a pop and a whistle like sound (much like air coming out of a tire) from the rear end, tires fine but now sounds a little chuggy, getting 320 to 350 to a tank and sluggish. I know you all have the answers for me... I always put between 91 and 94 octane in although I doubt it is the gas, wanted to get your expert opinions before the dealership gives me theirs
thank you!