invest in a K&N air filter

[mcrews]

Originally Posted by Cobb

I purchased the crz kn cai and put it on my insight. All I can say is VROOMMMmmmmm. Its noticeably louder and there is a chang ein the power band. It no longer seems to hyperventilate as you approach redline, but in fact keeps pulling. Unlike the maze the air had to travel through its just a piece of pipe bent at a 90 degree angle with a cone shape filter on the end. No improvement in mpg, but the butt dyno says yes.

Can't quite wrap
Around the idea of a sentence where redline and insight are used together...

[thesheet]

You are correct Red Devil, i am not a Spam Bot.
I think, therefore I am, (not a spam bot), most of the rest of you don't think. Your posts are hideous.
Disgusting.

You are correct Red Devil, I have been turned off this forum and shall vote with my feet.
Bye Bye

minus a couple posters here, you are the trolls....

[Frank Lee]

Oh how very sad.

[doviatt]

Wait, wait. Please don't go, yet. I'm interested....
Got some data?
What mileage were you getting before the change?

[ChazInMT]

Not Trolls, really. (Well, maybe Frank is a bit of a troll Frank Lee Selfie) Just maybe a bit wiser to how things function in automobiles and not really wanting to put up with claims that are unsubstantiated and to be sure, challenge the laws of physics.

If you came in here and said you were able to drive across a lake now because you just installed new tires, you'd get the same reaction.

In the intake for most gasoline engines, the throttle plate controls how much air the engine receives. This is set based on how much power you need, and the air required to mix with the amount of fuel being used. So, the variable here is power required to go a certain speed. The amount of power requires an exact amount of air.

Lets look at the 2 extremes for an air filter. If a filter is highly restrictive, then the throttle will open more for a given power setting than it normally would to draw more air through the filter, same amount of air enters the engine, same amount of fuel since the fuel injection operates somewhat independently of the throttle position. Thus fuel economy is the same.

If you remove the filter and have no restriction, then the throttle will close a bit, the same amount of air and fuel will burn for a given power requirement and again, no change in fuel economy.

Now if you want the most power you can get out of your engine for the greatest amount of acceleration possible, then without a doubt, a lower restriction on the air filter will maximize power output. But this does not mean it is more fuel efficient, it's a common misconception that more efficient an engine is at creating horsepower, then the more fuel efficient it is as well. If this were the case, then a Bugatti Veyron should get around 95mpg. They don't.

As some have tried to point out, the KN filter is awful at actually filtering the air going into your engine, somewhat large microscopic particles can pass through it such as tiny sand particles, these will act like sand paper on the wear surfaces of your engine and cause it to wear out much sooner than it would if you had a filter that stopped these bits. This is why the wiser among us will give up a few extra 1/10ths of a second in our 0-60 MPH acceleration in order to get a few extra 10's (100's) of thousands of miles out of our engines.

So there it is, the basic physics of why a 8% gain in fuel efficiency was not caused by an air filter change. If you look at my Honda fuel efficiency, it jumps from 28 mpg to 43 mpg depending on a whole crapload of variables, air intake restriction is not one of the variables. So, nobody is saying you didn't see a 8% change, they are saying it was certainly caused by something else besides the air filter swap, ie, driving speed, wind direction, traffic patterns, driving habits, and air temperature. Any of these could easily impact your mpg readings by 8%.

[Frank Lee]

Very funny- that's not me; I have a beard.

[RedDevil]

Originally Posted by mcrews

Well.....if your concern is real and sincere, then you wouldn't talk about her?(really..) like she's dead.
Instead, you welcome them and address them, laugh the other posters off and move on.
Unfortunately your post is lame

????

Why would my claim not be sincere?
Write like (s?)he's dead? I've reread my post several times, don't see that.
(edit) I was addressing the forum in general, not the OP (save the hyphened welcome) is that insincere?
I don't laugh at the other posters. I call for restraint.
My post is lame you say. In your eyes maybe. I shrug that off.

I think the way things turned out has already proved my point.

[user removed]

There is plenty of data that shows K&N filters do not provide the protection of an OE filter. If I drive my car through a whole tank of fuel and never see over 3500 RPM, why would I need more power (and less economy) than I already have.

The example I always remember is the 1.5 liter Alfa grand prix racer of 1950. Two .75 liter 4 cylinder engines bolted nose to nose with all accessories gear driven. 390 HP on 92cubic inches at close to 10k RPM. Two stage supercharging.

2 miles per gallon under racing conditions.

Power and economy is a great goal, but power means fuel and in the case of the Alfa a heck of a lot of fuel.

regards
Mech

[RedDevil]

It is obvious that the filter will have little impact as long as the throttle plate is used to restrict the air flow; a less restrictive filter would just be compensated by lifting the go pedal to maintain the exact same vacuum.

Nevertheless, there is no harm in some A-B-A testing.

Not A-B testing of course...
The official Dilbert website with Scott Adams' color comic strips, animation, mashups and more!

[Insight for life]

Im with you RedDevil. I can imagine being in the op shoes. There was a day I thought the world of k&n. And yes I wanted to shout it from the roof tops! I think it would be nice to break the new unknowing posters in a little more softly next time. He/she may never hypermile again because of crushed spirit, ok maybe it wont be that bad lol.