In my 90 Vert which only has 55k on the original motor and a K&N drop in, I get about 28-29MPG on the highway. I just finished driving from Reno to Colorado, and the whole time i was going about 80 and managed to get about 420 miles to the tank with an 1/8 left when i pulled into the gas station. I dont know why you guys have such low numbers, prolly because most of your driving is in the city. I know i cant get more than 20mpg on the 10th AE though.

 

1988 N/A GXL-some mods done-but orig. motor. 126,xxx miles.
In winter I average about 285 to a tank, and so far this summer I am getting about 345 to the tank. Basically looking at tyre pressure and you eat way more gas in winter with the increased stop and go with daily driving.

 

i usually fill up around 300miles per tank, but one time i ran out of gas and i had about 380 to the 18.5 gallon tank.

 

Best I ever got was 26mpg on my old very lightly modded '86 base/lightweight on 101 ~70mph.

Worst, I dunno- I have had tuning runs on my TII where it is tanks per hour.

Tuned the worst I have regularly seen is 9mpg on my TII on tanks that had an Auto-X race bringing the mileage down.