Engine Performance problem
2007 Mazda 3 4 cyl Front Wheel Drive Automatic 28000 miles
I got my oil changed at a local auto repair and they put 5/30 instead of the specified 5/20 weight oil in. I have driven just over a 1000 miles and realized my mileage has gone down. Should I be worried about damage to my engine? Would this cause the drop in mileage?