K&N Filters - Use 'em or don't ??

K&N Filters - Use \'em or don\'t ??

I am looking for ways to improve the mileage my wife is getting on her car. Back in May of this year, I bought her a brand new 2004 Jeep Wrangler. It has the 4.0L inline 6, and the 27.5" tires, automatic transmission. Thing is she is getting terrible mileage. I mean, worse than my Yukon with the Vortec 350 V8. Anyway, I had heard that the K&N filters are a quick way to increase breathing and thereby mileage.

Do you guys have any real life experience or opinions? Anything else I might try to do to help things out here, or is this the way things are?

Down here in Texas, it is hot all the time, so she is running the AC. Don't know if that hurts anything or not.

Re: K&N Filters - Use \'em or don\'t ??

aint sure the filter will help .and ive heard ac dont realy hurt cause if ya dont have ac on ya windows will be open caseuing drag

Re: K&N Filters - Use \'em or don\'t ??

I have had K&N's on my last 5 cars. I like them alot. I'm not really sure how much it improves gas mileage but they are going to last you forever. For under $50 I would try one.

Re: K&N Filters - Use \'em or don\'t ??

I use one on my car, a Contour SVT, and the butt dyno says I got a little HP from it. It also changed the intake sound so it is more throaty. I lost 1 to 2 mpg though.

My brother uses one on his G35 coupe and when he doesn't leadfoot it he actually gained a few MPG so I guess it depends on the car. It is kinda funny cause when we go driving the twisties, I go from an average of 22mpg to about 19mpg, he goes from about 27mpg to 18-19mpg. He does have a six speed compared to my five though which would really help make the difference for freeway driving.

Re: K&N Filters - Use \'em or don\'t ??

Here's my completely anecdotal reply: I've had K&N air filters on my '92 Honda Civic and my '02 Honda CRV since January. They haven't exactly turned into rocket sleds nor has my mileage increased any measureable amount. In fact my CRV gets worse mileage now but other factors are involved. I calculated the cost of buying and renewing a K&N vs buying disposable filters over the life of the car (I expect to get over 200,000 miles on both of them.), and I'll come out way ahead with the CRV although it may be too late for the Civic. And there's one more factor: I'm a tree hugger and I'm glad to keep that many more dirty old air filters out of landfills.

Re: K&N Filters - Use \'em or don\'t ??

IMHO the fastest way to gain MPG is to get rid of the 27.5 inch tires and go with smaller tires. Big tires rob power and lower MPG. So unless you go off road a lot I would get smaller less agressive tires. I doubt the K&N will add MPG It will add a some power though. I use them on both of my vehicals. Also what kind of MPG are you getting with that jeep? My main vehical is a 98 jeep grand cherokee with the 4.0 inline 6 and 17 mpg is typical but If I am feeling quilty for driving an suv and can nurse it to about 20-21 for avarage mpg. when I am towing with it I get about 15-17 mpg.

Re: K&N Filters - Use \'em or don\'t ??

A K&N may help a little, but don't expect a miracle. I use them on all four of our cars, and have used them on about a dozen different vehicles over the last 15 years or so.

Some other things to do to help out gas mileage:
-run lower rolling resistance tires and overinflate by 5-10 psi
-replace oil and trans fluid and ps fluid with synthetic
-lower the weight of the vehicle, remove all unneeded junk, sound deadener, etc
-drive the vehicle like a grandma, keep the rpm and speed low

Unfortunatley there is only so much you can do with a vehicle like a Wrangler, it has a lot of things working against you, like the auto trans, the 4wd, big tires, convertible (or is it a hard top), inline 6, etc

-Keith

Re: K&N Filters - Use \'em or don\'t ??

hmmm unneeded junk? I have to throw away half my vehical then! I am one creature that needs his creature comforts!

Re: K&N Filters - Use \'em or don\'t ??

If you do a little research, you'll likely find that OEM paper/synthetic filters are far superior in their ability to prevent the passage of particulates of the size (10-50 micron) that contribute the greatest to wear. K&N's (oiled gauze) and oiled foam filters DO pass more air... more crap, too.

Their main advantage is improved breathing @ WOT, which is why they're popular amongst the competition crowd - who expect high wear rates and common teardowns/overhauls anyways. At other than WOT, there's really little/no advantage.

If you're concerned with the engines longevity, steer clear of 'em - IMO (especially in a dusty area like Texas).

Running the AC will definitely knock a few points off of the MPG. As well, being a new vehicle and all - MPG should slowly increase over the first few tens of thousands of miles, as things break in. Keep the tires inflated up near the top of specs, too.

FWIW, my '94 Ranger PU w/4.0L v6 - 5spd manual - routinely gets 23-26 MPG on the highway. But it took about 50,000mi. before it crawled up that high.

Wonder what the EPA est. MPG is for your Jeep (on the window sticker)?? Those current ratings are generally pretty close to what you should be getting.

Re: K&N Filters - Use \'em or don\'t ??

I put a K&N on my 4.3L GM V6 didn't notice any improvement in MPG it does sound a little better at WOT. Keep your old filter as a spare to run while you are washing and drying the K&N that is a small PITA.
Later
Sway

Re: K&N Filters - Use \'em or don\'t ??

[ QUOTE ]
capnal said:
Jeep Wrangler.

terrible mileage.

[/ QUOTE ]

Welcome to the club, that sounds about right. /ubbthreads/images/graemlins/wink.gif

Seriously though, my Wrangler (2.5L w/manual trans) and Cherokee (4.0L w/auto) get nearly identical mileage; between 17 and 20mpg highway.

Adding a K&N air filter has made no measureable improvement. The Wrangler's main foe is aerodynamics (flat grille and winshield).

Re: K&N Filters - Use \'em or don\'t ??

[ QUOTE ]
capnal said:
Thing is she is getting terrible mileage. I mean, worse than my Yukon with the Vortec 350 V8.

[/ QUOTE ]

Slightly off-topic, but what kind of mileage are you getting in your Yukon? I've got a 4Dr 4WD K1500 Tahoe with the Vortec 350 running a 4" lift, 20" rims, and 33" tires /ubbthreads/images/graemlins/buttrock.gif but I still get around 14mpg. If the Wrangler is worse than that there might be some other problem.

Oh yeah, and I use K&N filters after the first filter change for environmental reasons, too. No real noticeable difference in normal street driving.

-Randy /ubbthreads/images/graemlins/cool.gif

Re: K&N Filters - Use \'em or don\'t ??

[ QUOTE ]
capnal said:
I am looking for ways to improve the mileage my wife is getting on her car. ...new 2004 Jeep Wrangler. It has the 4.0L inline 6, and the 27.5" tires, automatic transmission. Thing is she is getting terrible mileage. Anyway, I had heard that the K&N filters are a quick way to increase breathing and thereby mileage.


[/ QUOTE ]
Stay away from the K&N filters.
Drive right behind large trucks when on the hiway. The Jeep Wrangler is as areodynamic as a brick.

I got up to 22mpg at 70mph on the highway when I was drafting big trucks.
Can go as low as 16mpg if not drafting.

Dan

Re: K&N Filters - Use \'em or don\'t ??

when you guys say bad gas milage, what exactly do you mean?

my old car got less than 8. i can go over twice as far on a tank with this one! /ubbthreads/images/graemlins/grin.gif (which would still probably be considered pretty bad by some)
(it's a 95 dodge stealth, old one was an 86 plymouth gran fury)

i plan on getting a cold air intake for it, which shold both increase performance and fuel economy.

Re: K&N Filters - Use \'em or don\'t ??

to me k and n are just for cars or trucks that have agresive cams and wicked intakes and carbs and exuast to me they alllow for the extra air flow.on the common car with no mods i dont see the use but thats just my opion i could be wrong

Re: K&N Filters - Use \'em or don\'t ??

I bought a K&N way back when on an '80's 5-liter V8 Mustang when I was in college. Couldn't tell any difference either way -- sound, mpg, or power. I never bought another one and think they probably are today's snake oil.

Dontcha think that if there was "free" mpg gains to be had from something this simple, that the car makers would jump on it and install them from the factory? The Big 3 are hungry for ways to increase their corporate mpg averages so that they can sell more high-profit trucks!

If it seems too good to be true, what's that saying again??

YMMV (literally!)

Cheers,

Dave

Re: K&N Filters - Use \'em or don\'t ??

dyno tests have confirmed that these filters can improve mpg averages, that's about all i know.
i'm sure there are drawbacks and other reasons to not use them.

there are always little tweaks you can do to things to make them better, if a company were to do every little tweak, it wouldn't just end up being a little tweak, it would be a whole new car!
(although i've often wondered the same /ubbthreads/images/graemlins/icon3.gif)

Re: K&N Filters - Use \'em or don\'t ??

little tweaks add up that's for sure.

Re: K&N Filters - Use \'em or don\'t ??

get a fram filter change it regelry keep tires inflated keep car tuned etc etc

Re: K&N Filters - Use \'em or don\'t ??

I dunno...

I've noticed a jump in fuel economy and a little better throttle response in my 2000 VW Jetta (2.0 4-cyl auto). Before the filter i was able to get about 22-23mpg on the street, 28-30mpg on the freeway. With the K&N i'm able to get up to 26mpg on the street and upwards of 32mpg on the freeway.

I went back to a stock, paper filter just to see what happens...and after about a month, my fuel economy went down to about 280-290 avg. miles per tank as upposed to 320-360 miles per tank with the K&N. I went on a road trip once and was able to squeeze almost 420 miles out of my 13 gallon tank.

Now i don't know if the air filter was the only thing that helped my fuel economy. For the past 20,000 miles, my catalytic converter has gone bad. Pretty much, i think my exhaust system is working with a totally gutted catalytic converter, allowing more air to flow through the pipes with less restriction. I've noticed a signficant increase in gas mileage along with the K&N filter. But even without the cat problem...the K&N did give me some improvement.

One word of caution though if you do get one. When you clean it, or install it for the first time...DON'T OVER OIL IT. I had to get my MAF sensor replaced once under warrenty. I don't know if it was from the K&N or what. All i do know is that some people have had problems with the oil getting into some sensors and the computer started throwing some codes.

I would also believe what other members have said too. More air equals more crap...i guess that's just the way it is. If you really want performance gains, buy a cold-air intake designed for your car. If you can, maybe you can get one fabricated to utilize a hood scoop. But you'll never find me sportin' a hood scoop on my Jetta...too funky lookin'.

To help clean my engine a little more, i put some fuel detergents/cleaners and oil aditives. I don't know if they work...but my car is still running after 105,000 miles. /ubbthreads/images/graemlins/smile.gif