I have a 2009 Toyota Prius. Earlier today I changed the engine oil but made a mistake and used 0W-20 instead of 5W-30. I was tired and didn’t read the label properly. I also changed the oil filter, then drove around for about an hour. My mpg dropped to 20 and that’s when I looked at the bottle and saw the mistake. I’m now wondering if this could cause damage. Should I switch back to 5W-30 soon? Do I need to change the filter again too?
