Will mags with a 40mm offset fit on my Subaru Impreza 2.5i sport 2008

Look up what the stock offset is and compare the two.

The stock one is 55, usually you can go from 48-55 offset. but I was wondering if I could still put 40mm offset mags

40mm might make tires rub on the inside. Better to use something closer to stock but you could try one with a tire on to see.

I have 17 x 9 or 10 inch after market rims on my 2008 Subaru Impreza hatch with an offset of 37 the stance looks insane and the wheels stick out in the front. But the wheels always rub over bumps or potholes when there is a load in the rear person or cargo also when you corner fast the wheels often rub. Short answer the 37 is too low of an offset to run the wheels always rub a 40 might as well but I have only tested the 37