the best i ever got was in my moms 95 se auto, from NYC to north carolina i got like 475(approx) on a tank, it was at 440 and btwn a quarter tank and empty when i filled it again, so i think i wouldve gotten like another 50 miles even on those two gallons still left in there, so maybe even 500, im not joking either, i was cruising the whole way on interstate at about anywhere btwn 65-85..mostly around 70-75 tho...no mods on that car at all either, in my 97 tho, i dont get as good miles, but i went upto binghamton last week, it was pretty cold and raining, and when i reached half a tank, i read 258 on the counter, so that would be over 500 miles on the full tank? this is for highway driving only, going about 80 most of the way...in the city i get horrible miles, 15-20 MPG...but im quite satisfied with the highway fuel consumption in the max..

 

No, no, no Ny, you can't go by that "half tank" crap! (I'm not yelling at you, I'm yelling at Nissan). I can't speak for everyone here but here is my gas needle location vs miles driven:

At 3/4 tank: 150 miles (thus "indicating" a 600 mile tank range!)

1/2 tank: low 200s (thus "indicating" a 420 - 430 mile tank range)

1/4 tank: 300 (thus "indicating" a 400 mile tank range)

At/near "E": High 300s (thus indicating - well uh - high 300s)

In other words, the Nissan gas gauge is jacked!

 

i get about 325 before i start getting worried....but the gas light doesn't come on yet...i never tested it to the end....

I heard keeping gas low in your leaves a bad residue in the tank....

 

I think all gas gauges do this, not just Nissan. Unless they've improved, they used to work on some kind of lever with a float (it's been a long time since I worked on a gas tank). So, the scale isn't consistent as the angle changes ...

 

.....only a bit different when I was driving it in the summer (99% highway):

3/4 175
1/2 280
1/4 410

However, since we are having the snowstorm here in Wisconsin (60% city and warming up, 40% highway) in the past few days...

3/4 140
1/2 190
1/4 .....nothing sofar just yet....

That makes me wonder, does the outside temperature effects gas consumption? Especially factoring that the air is much colder (so it's not that easy to burn in the combustion chamber), and therefore the combustion is on the "lean" side?

 

yep, when it's colder the air is denser. this actually packs more oxygen into every cubic liter of air and your engine is actually more powerful. the ECU adjusts for the temperature change and riches up the mixture, so that's not really an issue.

 

Ouch sucks for you guys. In PA our supreme is 93, and you can even get "ultra" 94 from some places. So in PA it's worth the extra few cents over 89 to get 93, that's 4 more octane. I'm not really sure how much 93 helps over 91/92?