Hello everybody so recently iv noticed that my car burns alot of gas for some reason. and i do not know why. I dont have anything major done to the car. I only have 73km on it and i bought it with 56km. The things that iv done to my car is regular stuff like, 20inch rims, and little things done to my engine but could that be the problem. ? I have never done a tune up in along time but i do not think thats the problem either.

I put a Ztube in with a K&N filter. I installed it myself at home and its just making me so mad that my car burns gas like a god damn SUV. <<<<could this be the problem?

About 230km there is about a quarter left in my tank.



Can you please help me out on what to do. Thank you all!

Here is my car: http://img59.imageshack.us/i/user664...492124735.jpg/

 

my g35x gets about 320mi on a tank, which is the norm I think, so you are definitely not getting good mileage

What grade/type of gas do you put in?

 

i put the best one all the time. Nothing less then 91. Super as the call it here in Toronto

 

You need more asterisks in the title.

 

What kind of 20s? The definitely contribute to your gas mileage, the weight of them is going to burn some gas.

 

the lip is 3.5 inches. I thought rims would not affect my gas that much. im thinking mainly its my Ztube thats installed. Even though it sounds nice, i think i have to take it out and put everything back to stock

 

Yeah, definitely not your Z-tube that's causing that bad of mileage. Probably a combination of wheels, driving style, and possibly maintenance issues (filter, plugs, O2 sensor, etc.).

My X regularly gets over 300 miles/tank (480kms) and I've passed 400 miles/tank (640kms) on the highway.

You sure there's not a leak in your tank?

 

Yea my g35x gets about 250 miles or so on a full tank and i drive conservatively. I did a ztube, motordyne spacer, pop charger and 19" rays.. i get awful mileage. Anything i could do? What can i ask the dealer to check that may be effecting the mileage? Thanks.

 

Yeah me too. Very good question man. Can anybody help us? I want to go to the dealer also to find out what could be the problem.

 

Assuming you are using good gas and driving conservatively, I would have it scanned to see if any codes are showing. Also, depending on mileage and when the last time it was done, I would also change my filters, fluids, plugs, and run some fuel injector cleaner through the system. Has the fuel filter ever been changed? Not really sure what else you could do.

Also, 250 mi/tank is bad, but it's not unheard of. I've been in the mid 200's when all I do is stop and go city driving. It also depends on how low you run your tank down.

 

what fuel injector cleaner should be used?

 

To be honest, i'm very disappointed there is no user-servicable filter on the G35...at least an EASILY servicable filter.

The filter is in the tank. I hear it can be accessed by pulling the rear seat out, but it has no change interval.

In my experience with other cars, every 30K miles i pull out the old filter and replace it...and they flush the old one and crud ALWAYS comes out.

Kinda wonder what the tank filter will really look like at 100K miles

 

are you sure your tank is actually empty?.. maybe you have an issue with the floater on the sending unit. Its a known problem that many g35s face, my guage is off by 1/4 tank sometimes.

 

Any chance that the K&N filter was over-oiled and has contaminated the air flow sensor?

 

ooo thats pretty bad..
city driving i get around 300mi, and freeway stuff i get around close to 400 and i have injen short ram, with hrypipe, coupe midpipe, and an aftermarket exhaust... i highly doubt its the intake thats causing the problem. definitely get that checked out.