I got the 250 but it's bored out to a 261, 3 on the tree 1/2 ton stepside shortbed, so it's the lightest one possible.
I get 14 mpg drivin normal to school, about half city half highway.
I get 11 mpg if I goose it everywhere i'm going on the way to school, like if i'm running late (which always happens).
Now, for some odd reason I get the best mileage when I'm doing over 80 mph, and with only 3 gears the motors just screamin at this point. I wouldn't expect it but thats my best fuel consumption, go figure..
