Seems kind of long. When have you guys done yours? I did my first @ 25k, when I first got a couple tanks of below 45mpg. As soon as I changed it, I was back to 50+. I'm now @ 45k, and mileage is hovering around 45mpg again with really warm temps, going to change it tomorrow...
The general rule of thumb is to replace the air filter when you can't see light coming through as you hold the filter up to the sun. When I lived in southern CA I replaced the engine air filter at 15K mile intervals. Now that I am in southern AZ where the air is cleaner (except during periods of high wind), I think the filter will last 30K miles.
It is a two stage filter system. If you remove and look under the cover, you'll see the first stage filter. You replace only the second stage filter.
I thought the maintenance schedule called for engine and cabin air filter changes every 15,000 miles.
Nope nope nope! It is a single-stage filter system, and the filter that you replace every (nominal) 30 k miles is that filter. The thing that you see is (likely) an activated charcoal pack that absorbes any fumes that come out from the intake. Then, when you're running the engine, the intake air runs past it and pulls out the fuel that it collected. It's done that way to reduce emissions.
I agree- I've been told the first filter underneath the cover is a charcoal pack. According to my manual, the air filter and cabin filter don't get replaced until 30k.....I could swear all my other cars were to be done at 15k.
Prius ICE runs on Atkinson cycle, if it is running. Due to the late intake, its effective displacement is about 1.1 liter for gen2 1.5 liter. There are times when ICE is shutdown and not breathing at all. Those are the reasons I believe the filter has double the life.
Just replace them when it's dirty! I used to replace my cabin air filter once a year. Now that I'm in a dustier (and dirtier) place, I replaced it every 8,000km or ~6 months.
I could be totally wrong, but it still seems to me that air would be forced through the filter whether the engine is running or not.
The ICE air filter is ONLY working when the engine is turning. The passenger air filter is used at all times (except when the car is parked and off). Toyota says 30,000 mile intervals except in harsh use (yes, Arizona in windy, sandstorm conditions and California smog would be harsh). JeffD
The change in mileage wasn't due to the air filter. It has to be ridiculously clogged to even begin to have an effect on the mileage in a modern closed loop OBDII engine such as all cars sold in the USA since 1996 (IIRC). See here for an Oak Ridge National Lab test of the effects of clogged filters on gas mileage. Bottom line - no effect. Rumple
Interesting read. Some have suggested that the cabin filter somehow could affect mpg as well. Thoughts?
If the cabin air filter was very clogged, and the air conditioner compressor had to work longer than it otherwise would to cool the cabin, this would consume more traction battery power which eventually would have to be replenished by running the gasoline engine more. There is a link between the level of dirt on the cabin filter and mpg, but the effect of the former upon the latter would vary depending upon the ambient temp and your need for air conditioning.
I suppose the converse would be that in cold weather, a clogged cabin air filer would prevent less heat from escaping the engine and help improve mileage! I would suspect that either effect is down in the noise. Rumple
