K&N air filter

[seXterra06]

i got a 06 xterra S.....2wd.....auto with about 46,xxx miles on it. i just recently put in a k&n air filter in it and it seems like my mpg has gone DOWN. anybody know why? maybe there's something about these filters that i don't know about. any kind of input would help. thanks!

[leeroy300]

not to be offensive but are you doing like I did walking on it more to hear the sound differance and see if there is a power differance . I did a cold air on my titan and did not see any differance on MPG. It should settle back to normal after a tank or two .

[seXterra06]

no offense taken. i didn't think i was running it harder than before. i'm trying to keep my foot off the gas as much as possible and accelerate slower than i have been to see if it'd make a difference and it has so far. but i really haven't seen a change in MPG since the filter change. kinda disappointed...

[hsckris]

With 46k+ miles, you might need some maintenance.

Other things that could affect MPG:-Tire inflation-Using the correct gear-Keep the truck clean-Driving habits-Proper maintenance-Extra/excess weight

Also, the 4.0 runs better (& gets better mileage) on premium fuel in my experience.

I personally see an average of around 20 mpg in my 4x4 4.0 auto Frontier

[seXterra06]

gas is too expensive for me to use premium fuel...lol

i do alot of city driving so i hit alot of traffic lights. but i'm trying to find more highway routes and like i said before, accelerate slower which seems to have helped some.

[hsckris]

gas is too expensive for me to use premium fuel...lol

nissan recommends premium fuel. it says you 'can' use 87, but engine performance & efficiency will suffer.

[seXterra06]

really? hmm.....i may have to suck it up and give it a try then. thanks for the help

[xmetrix]

Lets do some simple math shall we.

these values are just example/estimated values.

87 octane = $5.00/gal = 20mpg = 0.25 cents per mile90+ octane = $5.50/gal = 22mpg = 0.25 cents per mile $5.50/gal = 26mpg = 0.21 cents per mile

So if you were to gain only 2mpg, you'd be paying the same price for the same distance traveled. If you gain 6 mpg, you're saving 4 cents per mile. or roughly 40-80 cents per fill up, all while running the recommended fuel grade which will promote better wear on your parts (o2,plugs, etc)

Think about it this way. If you could buy a gallon of gas that would make you car get 70mpg for only $10, you'd jump on it right away right? Just break it down into simple terms, Price paid per mile, not per gallon because what it all boils down to is how much distance you're getting out of your buck.

[Rev_D21]

I end up paying $.15/mile on 87 octane.

[S13xCrazy]

Even if you have a 20 gallon tank...the difference between 87 and 93 is $4

Not a big whoop in my book.

[hsckris]

Even if you have a 20 gallon tank...the difference between 87 and 93 is $4

Not a big whoop in my book.

Thats exactly my line of thinking -- and, at least here, its usually less than 4$.

Just to reinforce -- you should have done a lot of maintenance by 46k, I hope you have. At 30k I did belts, rear diff, front diff, trans case, trans fluid change, r&r air filter, along w/ the usual oil change, tire rotation (this is what Nissan recommends for the Frontier).

[bigdog]

i was told the "secret" to the k/n filter working on the new cars is after installing k/n drop in filer was to unhook the battery for about 30 min so the computer can reset the air flow reader on the engine. my wifes 2wd 07 x is avg is m19mpg in city & have gotten right at 25mpg on the hwy. Not to bad i'd say.

[Corradoslc7]

nissan recommends premium fuel. it says you 'can' use 87, but engine performance & efficiency will suffer.

That's just not true, I have read my owners manual from cover to cover and no where does it recommend anything higher than AKI 87 octane. Post up where you're seeing this information because I would love to see it. To answer the OP's question, K&N air filters have oil on them. That oil can get onto the filament of the MAF sensor and cause some faulty readings. Try cleaning your MAF (using MAF cleaner) and resetting the ECU by unplugging the battery. Good luck.
Modified by Corradoslc7 at 5:03 PM 7/26/2008

[Corradoslc7]

deleted.

[hsckris]

2005 & 2006 Owners Manual (Frontier)

Use unleaded regular gasoline with an octanerating of at least 87 AKI (Anti-Knock Index) number(Research octane number 91).For improved vehicle performance, NISSAN recommendsthe use of unleaded premium gasolinewith an octane rating of at least 91 AKI number(Research octane number 96).

2007 & 2008 Owners Manual (Frontier)

NISSAN recommends the use of premium unleadedgasoline with an octane rating of at least91 AKI (Anti-Knock Index) number (Researchoctane number 96). If unleaded premium gasolineis not available, you may use unleaded regulargasoline with an octane rating of at least 87 AKInumber (Research octane number 91), but youmay notice a decrease in performance.

[bigdog]

i've always noticed that the nissan v-6's run much better w/primium fuel in them. they idil much smoother w/primiunm also.

[BadQ45t]

The Frontier must be totally different that the XTerra. The X is rated only 87 fuel and the X-Terra owners forum several people attempted to try out premium and found zero benefit. The X 05-present are 100% designed for regular unleaded. You will have ZERO benefit using premium. The Frontier must or is different cause the X ownesr manual calls for regular, the dealership told me to use regular, and I have tried super once or twice and saw no benefit in power or mileage.

Usually your right that Nissan's run better on super, but in the case of the X don't waste you money.

[Arizona Hardbody92]

My hardbody gets better MPG at 91 octane than 87. runs better too