2000 Lincoln LS (stick) I get only 12.5 mpg city but 25 mpg on highway. Any other experience?

If it is a V8, that is about normal.

V6, I may suggest chasing a problem. They did have some strange fuel pump issues(they have 2 fuel pumps, a fuel pump and a jet pump)(dumb setup) but, they usually gave you running issues, not mileage issues.

I am not going to lie, the let someone else drive in the city with it is a pretty good idea.

Sounds like a driver issue.

You are accelerating too hard and/or up shifting at too high revs. Try up shifting at 1500 rpm, and as soon as you get into 5th gear, accelerate with your foot to the floor until you reach cruising speed. With this approach, you will be in 3rd gear by the time you are through the intersection.

I get 32-35 mpg on a 40 mile / 1 hour commute with a Ranger pickup with manual transmission, I up shift at 1200 rpm.

That is a huge difference.

How about letting someone else test that city MPG? That would definitely rule you out as the problem.

12.5 mpg wow you need a new car!!! you must be rich to afford those gas prices.... or you just never go anywhere!?

Double check your math.