The F18 is longer then 18 feet. (by almost 2 inches)
The F16 is longer then 16 feet. (by 5 inches)
Hell, even the F20 was longer then 20 feet. (by an inch)
We'll have to ask Darryl Barret about how long the F14 TRULY is.
Agreed the proposed F12 is longer then 12 feet by 10 inches and thus relatively more then the others but still it won't be the odd one out.
I apologise then, I'll wait til you tell us how long the F12 is going to be.
Again, what are you exactly trying to say here.