Blitz air filters...

Regardless of how efficient it is, it probably won't make any difference to fuel economy.

 

Efficient at what?
Air flow, filtration, or separating you from more of your next paycheck?

What problem are you trying to address with the filter....or more specifically, what do you expect to gain with the unit?

I'd stick with the OEM filter unless the Blitz LM Air Filter isn't much more than the OEM unit, in which case it MAY not hurt your car very much to try one out.
Usually "hi-flo" filters are more efficient at allowing air to flow through them at the cost of allowing more dirt to pass through as well.
People who race cars for a living aren't necessarily interested in getting 250,000 miles out of their motors, if you know what I mean.....

 

I have K&Ns in both of my Priuses (2005 & 2013), and also had one in my 2010. While I have had them in cars where they did make a difference in performance & economy (especially my 2003 Nissan Frontier, which gained at least 2 highway mpg), I've noticed no difference on the Prius.

I continue to use them for two reasons. In the long run they are cheaper to use (reusable when cleaned) than the OEM filter. Also using and reusing them saves the waste of throwing the dirty filters away. I do clean them every 30-35K miles instead of the recommended 50K, which is not free (costs about $2) or waste-free, but it sure beats throwing $15.00 worth of old filter away every 15K miles ( they were almost $30.00 when I first bought a K&N).

 

Be careful if you use the K&N. Stuffing an oily piece of gauze between your intake and your MAFS and your throttle body can be kinda rough on the intake system if you're not careful with the oil.
Use too much and you'll FOD out your MAFs and/or you'll be yanking your TB for a clean and inspect before 100K.
Use too little and you're going to FOD out your TB and/or injectors with the stuff that the oil didn't catch.

One trip to the dealer for a "spray and pray throttle body service" will eliminate the delta-$ that you achieved (?) by using the rag.
K&N has their place in the automotive world, and I almost respect some of the eco-weenies that are trying to do good things.....as long as they're not substituting paper and plastic in a landfill with oily water in the sewer system....

However (comma!) I'm a hard sell on using them on Priuses. If you wanna save money....order the OEM filters online and in bulk.

JMHO.
(Current street value....less than 2 centavos! )

 

I just cleaned my MAF, Throttle body, along with newly exposed engine components at the cost of an hour of my time and around $15.00 for an assortment of cleaners. The throttle body needed a serious wipe after the dealer "supposedly" cleaned it less than a month ago. Lets not assume we must choose to over pay the dealer to do the work.

I have had plenty of K/N filters on other high mileage vehicles and motorcycles without zero issues.

While researching the subject a ways back I found technical data to backup exactly what ETC(SS) said regarding paper filters having less flow, but doing a better job filtering the smaller particles.

This was a a big deal to me as I figured I would never own a K/N filter again. I mean why would you want to hurt your engine?

Then I asked a very good and smart friend of mine about the subject. This is when he twisted my opinion back around unexpectedly. His thoughts were that it is critical the air filter filters bigger particles from getting into your cylinder because they would destroy the cylinder among other things.

His opinion was that the K/N does great except for the very minuscule particles (as the data showed), but it's okay because the engine oil filter's job is to filter the microscopic stuff. The key with such a setup would be to change your oil at suggested intervals.

My buddy then told me while circumnavigating the globe on his motorcycle he briefly rode with a guy overseas who was at 70k miles on his Harley without running any air filter and it ran great. That input along with my personal experiences owning K/Ns cause me to believe it might be an intelligent purchase after all..

Thoughts??