I noticed the size of the engine air filter in the Gen 4 prius is at least 2x as big, maybe even closer to 3x as big as the filter in the Corolla hybrid, which has the exact same engine. Anyone know why the discrepancy? I thought everything about the 2zr-fxe engine was carried over. The filter size in the Corolla is actually really small and in the prius its huge for such a weak engine. EDIT - I might be mistaking the gen 3 air filter. Ether way, at one point the air filter size got reduced by at least half and I find that odd.
Mine is about 8.5x 7.3''. The air box looks much larger in photos in the gen 3 compared to the gen 4. Looks much larger than mine in the below video: 2009-2015 Toyota Prius Engine Air Filter Replacement (2009, 2010, 2011, 2012, 2013, 2014, 2015) - iFixit Repair Guide
You won't get the full story until you disassemble both filters and lay them out to measure the total square footage of filtration media. From an engineering standpoint, you usually want the largest one that will possibly fit in order to reduce pumping losses. If the underhood space just doesn't allow it, they have to compromise.
The air filter in the 20 Prime is the smallest one I ever had in a car. It’s still far bigger than the throttle body opening. It’s not cheaper from Toyota though. Walmart sells the Fram Ultra but it’s still an expensive size.
