low gasmileage ?
 

Hi all, i know that's a stupid question for someone owning a fc, but still, i believe i'm drinking a bit too much gas.
I'm doing around 12-13 MPG. I'm mostly driving through the city. I'm not driving with a light foot i reckon but i'm not street racing either... i believe there is some issue on my car. what do you think it could come from ?

o2 sensor ?
Tps (once warm the car idle at around 700-800rpm steady) ?
fuel filter ?
air filter ?

I do have some mods on the car but it hadn't really impacted the gas mileage since i have the car so i don't think it can come from this.

bonus stage : if i do have to change the o2 sensor, do you have any recommandation ? because my mazda dealer is selling it ... 250 € O_O which is for you i believe something like 300$. For that kind of money i believe i'm better off with a wideband...

I wish I could get 12 mpg. sheesh!

Your thoughts seems like the right place to start. Air filter is cheap. Then do o2. I shop at PettitRacing.com for parts like that and their prices are likely better than your dealer.

lol i think i can get cheaper than my dealer almost anywhere, they are amazing... They sell the dexcelia oil (dunno if it's the same name in US) twice the price that do the shop 80km away...
i got a combo wideband o2 sensor+a/f gauge for 160$ i think that's good value.

12mpg is not too much ? i've seen in the faq it says something like 15-16mpg on agressive drive.

12mpg in the city with a lead foot is normal, don't expect to get much more.

i would still be sure all the tune up items have been changed though for reliability sake and it may net you 1 or 2 more per gallon.

15-16 is maximum city, which is usually a pipe dream.

and spending $50 on oil and $160 for a narrowband O2 sensor with gauge that really doesn't tell you much, yet complaining about gas mileage is reverse thinking.

had someone in the shop complaining to me about the same, using $60 a week in gas to drive 30 minutes a day, i use the same amount in the mercedes which gets 30mpg highway, gas prices suck and there is no real way to determine how many stoplights you sat at for 5 minutes at during city driving. city driving is so random from place to place that city mileage shouldn't even be a real figure.

jump on the freeway for a hundred miles then refill and calculate your mileage for a real figure basis.

I'm not exactly sure what you meant but for the oil most of the rx "expert" around me recommanded this oil. You think it's not necessary ?

and for the wideband, it's a AEM gauge with a bosch sensor so i expect it to be working correctly. And I don't really want it to manage my fuel consumption, it's more to check the if i'm not running too lean in cold weather as the turbo pressure reach 0.8bar...

if it costs more than castrol GTX then yea, it's not worth it.

i figured the car was an n/a and the O2/gauge installed was a narrowband, a wideband on a turbo is a good idea. sometimes you gotta specify or be treated like all the drift kids who have been pouring in lately. :)

definitely give it a tuneup if you haven't. when i got my FC i was getting 12.5 mpg city. I pulled the plugs... i don't even think the bottom 2 were firing, replaced them and the wires along with the oil etc. and i'm running average 16.2 mpg city now. also, my car is NA.