Hello guys,

I just bought my car. 04 G35X with 76K and replaced one front wheel bearing, all new tires, rotors and brake pads, new castrol edge oil, new air filter, alignment etc.

So far the car drives smooth, tranny oil looked good but I have a really bad MPG.

I filled up with regular gas this time and mostly drove in the city.

I did not push the gas more than 4.000 RPM and its %80 city and %20 hwy (60 mph avg.) driving mostly AC on.

The road computer shows 13.6 MPG, half tank almost gone within 117 miles.

So is it normal or what can I do to make it better?

 

don't use normal gas, use at least 91 octane

is that 13.6 mpg combined that your getting?

 

I will switch to 91 with the next tank. Yes combined 13.6...isn't it too low? I read people getting 18 in city driving and 25 on hwy.

 

I get 24mpg combined (15gallons=360miles) in my Osiris tuned, Stillen CBE, tube k&n, new Spark plugs, Synthetic oil,91 octane...2005 cp 6mt...50/50 city-hwy

 

Have someone check your timing. While the timing chain never needs to be replaced, it could have advanced or retarded itself somehow.

 

Timing was the only thing that I had no doubt about when I was buying the car since its chain.

If that's the issue, damnn.

Throttle body? Spark plugs? would these help at all?

 

Also reset your ecu

 

I'm not 100% certain this is the best thing to do, but I would get the car onto a dyno to see what's going on.

 

You can try using MAF cleaner, reset ecu, definitely change spark plugs if you dont know their replacement history.

 

80% city.. if it's a lot of stop and go.. i can see it happening..also.. make sure your tires are inflated properly.. ~35 seem to be a good mix.

 

I will order spark plugs rightaway.....

now I have to look up how to reset ECU, and where to spray the maf cleaner...

any other idea yet?

also in this thread first 3-4 replies are almost as bad as mine. Should that be a relief for me or they just don't care about mpg? https://g35driver.com/forums/g-spot/...s-mileage.html

 

I'm on the same boat with poor milage but i mainly drive city to and from work. I mostly drive locally and lots of stop and go...plus a heavy foot on the gas sometimes.

 

I'm averaging about 18.5mpg in my AWD.. and I use premium, it's about 60% hwy 40% city for me.

 

I've never gotten less than 20mpg combined....and since my most recent tuneup 24mpg combined city/hwy (75-80mph avg...on hwy )

 

Make sure you stick with ngk platinum or iridium spark plugs.