2012 Subaru Impreza 2.0 gas mileage after valve springs down

My mom has a 2012 Impreza that recently (a month ago or so) had the valve spring recall done. Since it was done, her MPG seems to be down 5mpg. Is this a consequence of the new valve springs, or should she go back to the Dealer? The car is obviously otherwise out of warranty, and has 80,000 miles.

Also, given it has a Timing Chain - when should you do the water pump? Do they last longer, or should she be planning on having it changed soon? We always used to do it when the Timing Belt had to be done before.

How are you measuring mpg’s? If you are using the car’s calculations, it was reset when the battery was disconnected for the work. It will recover. If you are hand calculating it, there is a possible problem.

Change the water pump when it starts to leak.