So the other day I got my 2012 Audi A6 3.0T serviced to have the brakes looked at. It ended up being a bad break sensor which was quickly replaced and is now fine. In addition to that, the service center replaced the spark plugs, oil, oil filter and rotated the tires- standard servicing for my car at this mileage (115k). However, immediately after pulling off the lot I noticed a significant decrease in power. The car would ride in each gear for way longer than it did before, struggling to accelerate. I decided to test out the actual difference in power it was making by checking its 0-60. Before I had it serviced, the car did 0-60 in around 5.5-6 seconds consistently. Now, 0-60 in a whopping 12 seconds! That’s a ridiculous amount of time and can’t be a coincidence. I decided to return to the lot and they checked everything from the spark plugs, to the oil and oil filter again, and checked the car’s computer to check for any errors but found nothing. The guy at the lot said it drove fine however I just can’t believe that. Does anyone have an idea of what’s going on?