I've only had my 350 for a month now and do about 85-90% city driving with it and noticed something, although I might be imagining it..?
It really seems to me like whenever I fill my tank to full, the first 1/4 tank goes extremely quick while the 2nd quarter lasts a little longer and the 3rd quarter outlasts the first half together. I don't have any physical proof and haven't been taking notes or anything, just an observation that may be wrong. After noticing this on my 3rd fill up i decided to only fill my tank half way the next time which i did and it seems like what normally would have killed my first quarter should i have filled it up only went through one dash...
Does anyone else think this is happening in their 350 as well that does mostly city driving??

 

Mostly city driving here also... Have not noticed the same thing you've experienced. But now I'll keep a closer eye on it. So far only about 5000 miles. My 240sx does the same thing though. Just something to get used to.

 

Ive notice this in my IS 250, its strange...

 

does no one else besides sith and I think this is happening?

 

I don't think this has anything to do with actual gas consumption, rather it has to do with the gas gauge response being non-linear, at least partially because of the irregular shape of the fuel tank.

 

It is uneven//non-linear response. I get 140-ish miles on the first quarter tank. I wish that were accurate =(