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Discussion Starter #1
Old set up:
Z tube.
K&N round air filter jammed into stock air filter box.

New set up:
Z tube.
UTR CF air filter.
Deleted stock air filter box.

After changing my dirt covered K&M air filter back to my CF air filter. My monitors been reading 10.8 mpg at 75 mph. When I had the K& N installed I would get in between 14-18 mpg. (Yes, I know most speed limit is 65 but sometime I just can’t help myself) Then on local streets with the new filter it’s reading 8.5 mpg when I use to get around 12.-14 mpg.
I can feel a better throttle response and the sound is much deeper but 8.5-10.8 mpg? What went wrong? P.S. I’m driving it just like I did when I had the K&N.
 

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My engine is all stock except a K&N filter, I get 14 mpg average (measured by entering gas fill-ups into aCar app) I occasionally get higher when I drive highway, but I have a lot of hills in my local drive which brings my mpg down.

Ive been thinking about some of the engine mods listed here, but I don't want to lose more mpg
 

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I used to let my 2006 calculate MPG over 1000's of miles (rarely reset it) and i never got MPG as low as you both are talking about.

18.3 in mixed driving over a few thousand miles. Repeatedly... for years.

Right now i'm getting 19.7 in my 2010 - also mixed driving, some highway, some local.
 

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Discussion Starter #5
By all the feedback from everyone, I’m guessing it depends on the location as well. As for me, I’ve been driving pretty much over the same routes that I did when I had my old filter. Couple of days have passed since I installed the new filter and didn’t see any improvements regarding the mpg, so I gutted the front air flow portion, power duct, and front portion of the air filter box and wxtended a 2.5 inch tube into the back portion of the air filter box to have it act a heat shield. The set up looks so ghetto but the mpg has increased to 14.8-18.4. Once I see it jump to 21.8. I know I should just change it to a different intake system but with what I'm getting now. I'm very happy. I just have to make sure I never show off my engine bay. LOL
 

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Discussion Starter #7
Yup, I'm very happy with mpg now.
 

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FX55 said:
Yup, I'm very happy with mpg now.

**** wtf! haha good stuff

so what i need to do is RESET my mileage and trip meter = my fill up my tank, get kn air filter, get oil change with mobil 1 5w30 synthetic and a KN oil filter, run a fuel cleaner with my full tank of premium gas. drive it till empty and look at the MPG trip metre right?!
 

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Discussion Starter #11
you got me on that one effects. :twisted:
 

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You guys really have me confused. 13 MPG over what distance (how many miles)? That's horrible.
 

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effectsfortyfive said:
i have the 4.5 v8 - 13mpg after 100 miles
Having a FX45 explains it part ways but that still seems low to me. Were you traveling uphill both ways?
 

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i dont know why honestly i was getting around 13-14mpg city and hwy AND i always made sure in city to keep rpms NO HIGHER THAN 2500 .. id actually try to shift at 2000rpms i dont care about traffic behind me haha i dont have a heavy foot thats forsurei just get crappy mpg.. i dont know how i can change that.. i use 91 chevron premium fuel ALL THE TIME I GOT BRAND NEW TIRES PUT ON LAST WEEK. i am DEFINITELY due for a wheel bearing however i dont know which one and after wheel bearing i have to do an alignment or so they say. so u think those things are affecting my MPG? also ima go get me a KN drop in air filter. probably be better by half a mpg. help>?
 

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u guys may think this sounds really stupid but here in canada i spend about 120 - 140 on gas a week for the fx45 -- that doesnt seem normal - because i use to have a maxima 3.5 same engine as fx35 and id only spend around 80 bucks tops.. running REGULAR gas.
 

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The wheel bearing MIGHT cause a small drop in MPG cause of the friction but not THAT much... and since you're in Canada, I assume you're using MPG and NOT L / 100km?

Check to see if any brake calipers are seized... that'll cause bad mileage... rears are bad... especially with Canadian winters... other than that, there might be something wrong with the engine...
 

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engine pulls strong - no hesitation no delay- oil change was done, yeah i converted it to MPG cause i know most you guys are americans :D haha so yeah.. anyhow datman

what causes MPG to be so low.. i know for fx45 in the city i should get somewhere between 12mpg-16mpg correct? i mean im lucky to get 13mpg.. and i have a really light foot and i mean LIGHT. alwayd under 2500rpms. .. my alignment is off i need to do wheel bearings and also need a KN drop in air filter.. not sure after those things i am able to get 1-2mpg better.. that will put me at 15mpg for city which is okay..

how do i know if my caliperse are seized.. will i notice it? any symptoms? and wat are the solutions!
calipers being seized in the rear..are one of the signs when u release your foot from brake at a red light and start to gas u feel as if its rubbing against brake pads in the rear?
 
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