K&N filter?

Hi WHCSC, K&Ns are great for increase in horsepower at high rpm/high velocity..free horsepower, by making the engine breathe easier. Their performance graphs are on the dyno at max rpm.
But the advantage would likely be marginal in our gen1's which do not turn up high revs and are not gasping for breath.
Best performance/mpg enhancer I have found is alcohol free gasoline, high tire pressure, ensuring rear brakes don't drag, and using new windshield wiper blades. R.

 

I'll agree with K&N's ability help the engine breath better, but how does the oil you put on the filter affect the throttle body of the Prius. It's caused havoc on some of the other vehicles I've owned so I won't try it in my Prii. That's my one concern.

Does anyone have any information on this?

 

Hang on, was that a test, to see if we're awake?

 

New windshield wipers are by "newness" more aerodynamic.
TomK

 

I wondered about that, but new windshield blades really do enhance performance... you can see where you're going. I however totally endorse Aquapell and RainX. Go HERE to compare the two. I favor Aquapell.

 

Way back in 2003 when I got my 02 some Prius folks were recommending the K&N filter as a mileage increaser. So I got one to try out. After a year or so as more data came in on it's effectiveness in the Prius (as noted above), I took it out and went back to the OM unit. I didn't see a drop in mileage.

 

Read this in its entirety (its not long). Its an objective, and scientific test performed on nine air filters, one being a K&N.
http://www.nicoclub.com/archives/kn-vs-oem-filter.html

"However, if a filter is using “better airflow” as their marketing tool, remember this….Does it flow better? At very high airflow volumes, probably. BUT, our engines CAN’T flow that much air unless super-modified, so what is the point? The stock filter will flow MORE THAN ENOUGH AIR to give you ALL THE HORSEPOWER the engine has to give. And this remains true until the filter is dirty enough to be recognizeable. At that point performance will decline somewhat. Replace the filter and get on with it."
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The factory engine is a balanced system (a compromise of performance, reliability, and efficiency). Air filter all the way to the exhaust, don't forget the programming. Add a K&N filter, the system is unbalanced. To maximize the potential, additional air flow increase K&N can offer, one would have to change out many other parts; exhaust system for sure, as the stock exhaust is very restrictive compared to a "performance/racing" exhaust systems.

Formula 1, Nascar, and Rally cars, are probably using K&N or something comparable. But those aren't normal everyday engines. Those bad boys are built from the ground up around performance, and cost a pretty penny. Penny is an understatement. I was off by many factors, when I searched "cost of formula 1 engine." 2014 F1 engine: average price $7.7MILLION (I'm assuming USD, as no currency unit is stated). LINK

We are driving a Prius. Not a sexy car, nor a fast car. But sexy MPG.

 

I used a K&N before in a different car, I can't say it's worth the trouble for me. The cleaning and oiling was a pain. The Toyota filters can be purchased for about $12 every 20,000 miles. The cost savings is minimal and just not worth the work involved in cleaning and oiling. I didn't notice any power difference when I used it.

 

Our original engine air filter is nearing 48000 kms, looking so clean I can't bring myself to change it. I'm guessing I'll snap around 60000 kms.

 

Gas Mileage Tips - Keeping Your Vehicle in Shape
Last section, clean vs dirty air filter doesn't change mileage. If a clogged airfilter doesn't hurt, then I think its safe to assume that a freer-flowing one wouldn't help. Diesels would be the exception, as they don't have throttle plates that restrict the air anyway.

 

Once a machine gets engineered up in this level of efficiency, it gets harder to improve on it's efficiency, and improvements are marginal.
Also, the higher the mpg, the less the dollar savings per new mpg saved, law of diminishing returns.
For a big pickup truck getting 8 mpg, a 1 mpg increase saves a lot of money in a year, but the same increase on a Prius has only 1/6 the financial benefit.
If anybody can come up with a good gas saving bolt on for Prius, I'll stand in line with you to get one!
Chapman has pointed out in different ways, that the biggest efficiency loss on Prius is driving during warm-up while the engine is in open loop. If you used an engine heater to preheat your coolant before every cold start, you would boost your mileage most of anything you could do...if the payback covered the Kwh used.
I am considering putting a 1Kwh heating element in the cylinder head with a high limit thermo switch inline, and a contactor actuated by the power door lock receiver. If I plugged the car in whenever I get home, I could click the key fob 10 minutes before I leave the house and have a warm motor and instant heat at the defroster.

 

We're using the block heater year round, almost without fail, for the first cold start of the day. Besides the faster warmup, it also imposes a behaviour change, makes you reconsider frivolous trips, or opt to use leg power for a short errand.

 

I think you'll get longer engine life, too, as most engine wear occurs during warmup, when the lubrication on cylinders and guides gets diluted by enrichment fuel. And you're not getting excess fuel passing the rings, diluting oil in the base. Probably a candidate for extended interval oil changes, analysis would tell.
When I was in the service, we kept the hot starts on our patrol boats plugged in 24/7 for easy starts and fast getting underway.

 

Linked article reinforces the truth, that is unfortunately drowned out by all the marketing, and auto pats store wanting to increase profit margins w/ the expensive K&N type filters, and filter oil. At least we know, and can share this knowledge.

The Nissan club testers, found the K&N filters let more particles pass through and gets clogged faster, than the cheap, but effective paper type filters.
Filter Efficiency (How well does the filter capture debris.)


Accumulative Gain (Total amount of dirt that passed through the filter.)

 

Got my air filter element off Ebay for $6. delivered, tho I use an upgraded oil filter to last for the 10k synthetic oil change interval.
I wonder if the factory plastic air cleaner also protects against high water or splash better than a K&N. And I just saw a link on Green Hybrid where contributor says oil residue from his K&N caused the MAF to fail.

 

I think LRR (Low Rolling Resistance) Tires is one bolt on item that has helped some. Arguably, the Prius drove this tire market segment.

Have heard the same about the engine block heater improving gas mileage during winter. Another added benefit, instant/near instant hot cabin heater.
Prius Chat Shop has a simple plug in type, $60. LINK If one has a garage, an extension cord plugged into this heating device, and the other end plugged into a timing device to turn on say 30minute before you leave for work? Just remember to unplug the electrical end on the car before driving off.


People who seem to know more about a block heater, seem to say that it is a bad idea to attempt to use the Prius battery to power this block heater; cheaper to run the engine than drain the battery. LINK

 

I'm guessing that's a situation you would want to avoid at all costs. Even if K&N could be proven to be superior in water absorbtion. Any water that enters the intake and gets into the cylinders, can make for a costly repair.

K&N says its urban myth, and has supposedly tested the failed MAF sensors: NO K&N filter oil was found on these sensors. I could see someone applying too much K&N filter oil, resulting in a failed MAF sensor. I would have more confidence if they gave these sensors to an organization like Consumer Reports or Under Writers Laboratories for unbiased and independent testing. Fox watching the hen house and says all chickens are fine.

 

Thanks! Just read the block heater ad. Anybody know how high this sits in the engine? I really want to just heat the coolant in the head, to stimulate the ecu's coolant temp sensor, not the whole water jacket down around the cylinders. Agreed this can't be done right with HV battery power, tho I think I could make my fob remote trigger the 110v. power on. Not so much worried about using it in winter, but all year, as Lesik, and my MFD indicate.
The article I read on K&N/MAF I don't think it wrecked the MAF, just made it sticky enough to pick up "whiskers"...cleanable.
I like the idea of LRR tires, but couldn't pass up Goodyear Viva 2 tires at Wal-Mart for $200/ full set installed...a set of LLR tires is likely double that-I'd have to play with the calculator to guess how much more MPG I'd have to gain with LLR to wash out the extra $200. initial layout. But sometimes I will spend more for efficiency even if the payback isn't there, just because I like to read the numbers.

 

Um, I think I said most of that, but not the open-loop part. What I tend to see with a ScanGauge is that even from a cold start, the ECU transitions from open to closed loop control within something like a dozen seconds. Mileage is bad for about the first five minutes. Bob Wilson has graphed volumes of data showing how bad and why.

I think the engine-block heater sold by Toyota is more like 300 W than a kilowatt. Advantage is it fits right into the recess designed for it. You can find a lot of threads where people have gathered data on how much benefit comes with how many minutes of preheat. If I remember how it fell out, you might want a timer to start it one to two hours before you plan to leave.

I'd question how much benefit you'd get just by fooling the water temp sensor. I think the reduced efficiency during warm-up is more because the engine is cold, not so much because it thinks it's cold.

-Chap