16:1 vs. 24:1 steering

16/24= .666

So you will have to apply 33% more effort to turn the wheel

16/20 = .8
So 20% more effort

20/24 = .83
So 17% more effort.

I can palm steer my 67 Dart (273, 215/70R14 tires) in a parking lot (but just barely) most of the time it is hand over hand.

At over parking lot speeds there is no issue
That's a pretty good analysis. Which gear box does your car have?

The tire size also plays a pretty big role, too. The wider they get, the more the effort increases. When I was younger, I used to like turning lock to lock in like 3.5 turns. Now I just don't give a damn anymore. lol I can palm steer Vixen sittin still and she has a smaller than stock wheel. I kinda like bein able to do that. She has the 24:1 box. I like it because if Kitty wants to drive, it's easy for her. It only takes a few more turns. How big a hurry are people really in?