I usually get ~300 mpt but lately I have been getting ~200. I have not changed my driving habits at all. It just all of a sudden dropped. Does anyone have any ideas as to how to fix my problem? I was thinking it could be the fuel pump, pcv valve, or injectors. All ideas are welcome and appreciated. Thanks for your time.

 

im having sort of the same problem i used to get about 380 to the full tank in my 2000 i30 but now im getting somewhere in the range of 280-300. it might be just lower quality fuel maybe, but not too be certain.

 

i get about 21 mpg

 

My i30 trip odometer and master odometer stop during half of time, so I got worse mileage than all of yours Maybe that's also your reason?

 

Have you been messing with the OD lately? I know that when I drive with OD on, I get about 300 a tank, but when I have OD off, it goes down to about 230 or so...just an idea.

 

i had the same problem the dealer said that in the colder weather they add some stuff to the gas so that the gas lines at the stations dont freeze and thats y you get crappy millage i dont believe them

id get your car checked if i were you maybe soemthing is misfiring or soemthing
good luck

 

i have never played with the od button

 

ahh...makes sense...my car had a hard time starting one time...wonder what caused it..

 

Never listen to the dealer! Replacing the fuel filter will help your gas milage, but what you really want to do is replace your o2 sensors and possibily your knock sensor. I used to get about 280 per tank on a highway/ city combo, but after rplacing the o2s and KS, I get about 380! and that stuff can go bad with out tripping a CEL. It makes all the difference.

 

how much did you pay for replacement o2 sensors and ks?

 

yeah how much and mine is cali spec i think , so i have alot of o2 sensors right?

 

i filled up today and i got about 23.5 miles per gallon on that tank

 

I'm not sure about the knock sensor, but the oxygen sensors can be found at www.oxygensensors.com. It looks like they range in between $45 and $90, depending if you want OEM or universal fitment. From what I understand, it's an easy install too.

 

i noticed that the tripometer rolls everytime i start the car...

 

I get 26-27 hwy and about 20-23 city.

my mileage improved after o2 senor replacement and re-programming the ECM

 

hehe...my mileage went down with the install of the cattman catback...i think its cause its new and im loving that sound!

 

I'm thinking bout replacing my o2 sensors, knock sensor, fuel pump, fuel filter, pcv valve, and fuel strainer. I *hope* that my gas mileage with significantly increase. Has anyone had experience replacing any of those parts? Is it hard replacing any/all of those?

 

45 to 90 is quite a bit for just a mild improvement of gas mileage

 

I paid about $150 for all three o2s and about $125 for the KS off of everythingnissan.com. Total savings off list was $225!! I also have replaced the fuel filter and pcv valve, but those are relatively cheap. Why do you need to replace your fuel pump though?

I saw about a 5mpg increase from replacing all of those. So it is definitely worth it.

The instructions are in the 4th gen stickies, it is really easy. If you have a shop do this stuff prepare for a $1000 bill!

 

DONT GO TO S.A. their gas sucks i literaly can watch my fuel needle move down on the highway when i use their stuff. I always go to newer Holiday on 85th and cr81 its the cheapest place in MG and they got 93.

 

Dude i usually go there too. You wanna help me replace my o2 and knock sensors soon? I'm looking for some help.

 

SA?


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