Changed air and cabin filters at 32,000 miles

[cary1952]

They were both totally filthy. The cabin filter had a mice's nest out of rope started. I wonder how much a dirty air filter can kill gas mileage. Mine has dropped 15-20% the last 10,000 miles. Though i have been using it almost totally on the highway, or in 10 minute or less trips the last 10,000 miles.

Anyone know how much a dirty air filter can affect mileage?

[JimN]

Originally Posted by cary1952

They were both totally filthy. The cabin filter had a mice's nest out of rope started. I wonder how much a dirty air filter can kill gas mileage. Mine has dropped 15-20% the last 10,000 miles. Though i have been using it almost totally on the highway, or in 10 minute or less trips the last 10,000 miles.

Anyone know how much a dirty air filter can affect mileage?

Don't know. In my Oldsmobiles the answer is somewhere between "not much" and "zero". You've got the situation so you should be able to tell us. I'd be interested in finding out.

[morpheusx]

I've read on various websites (autozone and the epa) that a dirty air filter can take 10 % of your mileage. I believe that is probably a stretch except unless the filter is almost completely clogged. In the past on my previous cars I would change at about 50,000 miles and would only notice a very slight difference. I would go from 32 MPG to 33 MPG on my 4 cyl. Eagle Talon. But on the other side though a dirty air filter will rob your peak horsepower significantly on most vehicles and typically after you replace your air filter you immediately notice the power difference. (probably wont on the Prius)

[Jiipa]

Let us know if your mileage improved after changing the filter.

If the filters were that filthy, you may want to change them more often, maybe at 15 or 20 K.

[dogfriend]

The Scheduled Maintenance Guide for 2007 says to change the engine air filter at 30k, but if you drive in dusty conditions, you are supposed to check it every 5k (each oil change) . I replaced mine at 15k, the engine air filter was a little dirty, the cabin air filter was very dirty.

[cary1952]

I get my oil changed every 5000 miles, and they have never said anything to me about the dirty air filter. Probably because if they did check it , it was cleaner from the top then it was from the bottom. As far as the cabin filter, looks like some mice were trying to build a nest in it, as I found a bunch of chewed up rope in it. LOL.

Cary in South Dakota

[dogfriend]

Originally Posted by cary1952

Probably because if they did check it , it was cleaner from the top then it was from the bottom.

Cary in South Dakota

Yes, for the engine air filter you would actually have to remove it and check the bottom side because the air enters underneath.

It really depends on your local conditions.

I could have cleaned mine and replaced it at 15k, but I already had the new one on hand and I bought it online (metrotpn.com), so it was not that expensive.

[Walker1]

Originally Posted by cary1952

They were both totally filthy. The cabin filter had a mice's nest out of rope started. I wonder how much a dirty air filter can kill gas mileage. Mine has dropped 15-20% the last 10,000 miles. Though i have been using it almost totally on the highway, or in 10 minute or less trips the last 10,000 miles.

Anyone know how much a dirty air filter can affect mileage?

Depending on how clogged it is the MPG can drop quite a bit. Think of yourself wearing a paper breathing face mask that's unblocked. Now think of how much air you could breath into your lungs if the mask was almost completely blocked with debris.

I live on a dirt road & my Air & Cabin filters were filthy @ 29,000 when I replaced them. Oddly enough the MPG didn't drop. Maybe the Prius knows something I don't know.

[Patrick Wong]

Originally Posted by Walker1

I live on a dirt road & my Air & Cabin filters were filthy @ 29,000 when I replaced them. Oddly enough the MPG didn't drop.

Well, if you drive gently as many Prius drivers do, then you usually are not requesting much power from the ICE, hence a clogged air filter may not manifest itself in driveability issues.

The clogged air filter will be an issue if you are flooring the accelerator, trying to climb a mountain grade at freeway speeds, and wondering why your Prius doesn't perform.

[Walker1]

Originally Posted by Patrick Wong

Well, if you drive gently as many Prius drivers do, then you usually are not requesting much power from the ICE, hence a clogged air filter may not manifest itself in driveability issues.

The clogged air filter will be an issue if you are flooring the accelerator, trying to climb a mountain grade at freeway speeds, and wondering why your Prius doesn't perform.

You're right. FL is flat as a board-no hills or mountains. I usually don't go over 20 MPH on the road as it's like a dust bowl when dry & the crap that's thrown down & graded on it has stones in it. I will NEVER live on a dirt road again!