Buy a Scan Gauge II.

I keep it plugged in, and Velcro'd to my visor. Give you instantaneous MPG, AVG MPG, Trip Fuel Cost, all for the day, previous day, and TANK.

http://www.scangauge.com/

I don't have any ties to the company, but between all the gadgets I have in the car ('side from my Valentine one) this one is my favorite for sure

 

I have hit 420 miles one time on a roundtrip driving 75-80mph on I-5. Usually i get 23mpg with 50% highway and 50% city. I usually wait until my light turns on before i put gas and i have never feeled up more than 17 gallons and they have a 20 gallon tank. Technically according to nissan/infiniti they can potentially get 500 miles on a tank of gas if your driving like a granny.

 

That's cool I like that a lot.

 

I'm getting 20 mpg

 

420 is a good number...

 

IMPOSSIBLE... even driving granny

 

All I have is a Z-Tube and K/N filter and I average around 380 miles a tank... I shift around 3k. There's been many times I've gotten over 400 miles on a tank. About 40/60 city to highway driving.

 

I just filled up today. I had 455 miles on the OD and put 18.9 gal in.

 

Filled up today 406 miles needed 17.6 gallons. Roughly 23 mpg, best I've ever gotten. It was 50/50, highway/city driving. First tank I've filled up since I installed my Bassani true-dual. I do floor it every now and then since I bought my catback.

 

to the OP..i drive pretty spirited in my 5at and get almost 405 miles on every fill up..

 

^ +1 on the typme M's

so yesteday I filled up after the light, 17 gallons went in, I averaged 18 mpg, so if i pushed it at 20 gal a tank i could have made it to 360, next time I'm gonna push it more, I do have AAA so they can bring me gas haha.

 

i just averaged 29 mpg according to the navi on a 180 mile trip. mostly coasting at an average of like 72 mph or so. so even according to the navi if i continued cruising around i would get over 500 miles to the tank.

 

lol Ill update with what i get just filled up FULL on Wednesday
and so so far I have 108miles
I'm 2 marks above half tank but I dont really drive slow unless I have to
but I do cruise in neutral a lot so I hope for 250 and Ill be kinda happy
then ill have to aim for 300 and so forth

 

06' LR AT 17" stock

I drive about 80% highway, 20% city and I get about 400 miles per tank. I usually drive about 75 to 80 MPH, and I use the cruise control as much as possible. I rarely run my air conditioning (Auto Econ), because I think this saps the gas milage considerably.

My car is completly stock, and the tank is definetly 20-gallons. The light comes on at about -16 gallons (4-gallons left).

Next time you fill up, note the milage on your car. The next time you fill up, again note your milage and how much gas you put in your car to fill up. If you subtract the two milages, you will have the number of miles you driven, and how much gas you used to drive those miles. Divide the number of miles you've driven by the number of gallons it took to fill your tank and you have your milage. If you do it this way it doesn't matter if your tank is 16 gallons or 20 gallons.

 

Mine varies, BIG time, lately its been like 250-300 per tank, but I've hit 400 before, funny thing is driving doesnt change much. Its not consitent at all ; ( On a full tank, sometimes the 1st 1/4 tank will get like 100 miles, sometimes I'll get as little as 35 ; (