Hey guys, so I'm wondering if I have the fuel gauge issue that other people are having. The car in question is an 06 G35 coupe 6MT, with nav so it has the mpg calculator. The reason I'm not sure if I have the fuel gauge problem is because I'm still on my first tank, but I've driven ~225 miles so far, and my gauge is reading maybe 1/8th below half. If I had to guess I'd say the driving has been split 60/40 hwy/city. Now, when I first started driving the car, I was still learning, and the mpg calculator was showing me 17.9 mpg. Now, it's gone up to 18.1. During this whole time, the estimated range would fluctuate, generally trending down, but sometimes it would increase and tell me I have more miles. This would happen while the estimated mpg stayed constant.

What can I do to tell if I need to clean the sensors? I'm thinking I'll go fill up in another 50 miles or so, then calculate the actual mpg from that. How closely should this match up with the estimated mpg on the nav? Is this all I need to do to to diagnose the fuel gauge?

 

If i remember correctly, your trip computer fuel range is calculated by fuel economy and whats left in the tank. (Mpg × gals left in tank=fuel range) I think it updated every 25 miles. So if you got slightly better mpg within that 25 miles your fuel range will increase. Now Our fuel guages are kinda wonky. I find they only work correctly when you fill up the tank.

 

So the estimated range displayed is reliable?

 

Did you start with the full tank of gas? And did you reset the trip meter when you filled up? If you did both, then your gas gauge seems fine. 225 miles with 1/8th below half sounds about right for normal driving. The gas gauge issue other people have is that the gas gauge needle actually fluctuates all over the place, like from 3/4 full tank drops to 1/4 tank or less then comes back to half tank, so if your gas gauge behaves linear as the mileage increase, then you do not have the issue, at least not yet (knock on wood).

Now the estimated range is another story. It's related to the gauge but it calculates the range with how the car is being driven at the moment, so it's normal that it fluctuates. For example, given your gas gauge does read accurately, you will see the range increase after you get on freeway from stop and go city traffic. Hope this helps.

 

Gotcha, thanks for clearing that up!