I've never had that happen and fill it to the top all the time in both of my vehicles. I've switched to Conoco/Phillips 94 octane premium. They opened a new station that sells 94 octane. I never get 15 MPG in the city and I never get 20 MPG on the highway either.

i agree and it can happen. there is a place in the manual that tells you to not overfill after it has stopped...for good reason.

Impressive Highway Mileage
 

Interstate 95 between Trenton, NJ and Philadelphia, PA at about 65 MPH without using cruise control.

This truck, despite having a 4.6L V8 under the hood, gives impressive gas mileage compared to cars with 3.0L V6 from 10 years ago. I know it's not a very good comparison, but today's V8 is actually more efficient than an old V6! I get 15mpg from strict city driving, and my friend's 4Runner V6 from the mid-90's is doing 12-13mpg!

will routinely get over 20mpg on highway easily. city however only about 14

I get 15 city, and on my last highway trip @ 80 MPH, I got 18.6 MPG. Better than my 2001 Infiniti 4 liter V6. I got 14 city/16 highway. The GX does have a 6 speed transmission compared to the 4 speed in my old QX4. One thing I don't like, when going up hills with the cruise control on, it kicks the transmission down a few gears and really revs the engine. I have to kick off the cruise control on hills.

Damn you guys are lucky, so far my City driving gets me only about 11.4 MPG :(

My GX 2011 , avg about 16.5 MPG

Location,location,location....:) Don't expect the same "city" mileage in NY as other parts of the country, well maybe LA....

Are you running premium fuel? I run 94 octane premium...

Yeap, Shell V-power.

I'm from LA- Gas: premium Cosco gas

I've logged a 400 mile turnpike trip with average speed from say 65-72 or so, and my mileage was just under 23. I measured it with the fill up method and got the same number.

Its all in the 6th speed. Not a lot of power up there, but certainly is effecient.

Around town I think I am getting about 17 mpg or so.

I'm consistently averaging 14 and change. Sigh.

I got 16.8 mpg towing a 4200 lbs trailer.

Koz