After all of this talk about overheating, it makes me wonder if I have an underheating problem. My temperature gauge is always near the very bottom of the central green scale. It only gets up into the middle of the green right before the thermastat opens. (of course after shutting off the engine, the residual heat in the block will eventually get the gauge up in the red)

After I go on a freeway run and get off on the offramp, my engine almost always starts to die unless I give it some gas or pull out the choke just a bit, this is due to my engine getting too cool. It also takes forever for my car to warm up enough to put the choke in all the way.

I tune my car at the temperature it gets when it's idling for a while. But once I am cruising for a while the engine cools down to a point where it doesn't idle well. Come to think of it, sometimes it acts like it is running a little lean when I am on the highway.

Is the ideal to have cruising temperature the same as sitting idle temperature?

I haven't tested my temperature gauge, and I don't know what thermastat I have in it right now. Can I get the cruising temperature and the standing idle temperature the same by simply replacing the the thermastat with a hotter one??

Any thoughts or ideas on this subject would be greatly appreciated.