I just replaced my engine and cabin filters on my 2010 prius with 30,000 miles i watched the you tube instructions for replacing the cabin filter... It showed a plastic tray that the filter fits in...mine didn't have one... I tried to install the filter with the slots sideways, but it wouldn't fit, so i inserted it with the slots longways....everything seemed to fit, but my mileage has dropped about 7mpg.... I know the prius is different than other cars, but can't figure what could be the difference..... Does anyone have any info that might be helpful?
The cabin filter change cannot drop your mpg by 7. The 2010 does not have a tray, the filter just sits in there and the cover keeps in centered.
