Engine runs cold, new thermostat didn't fix it

[bakguns]

I noticed that on colder days (<50F) my car runs cold especially on the highway. When it is in the 30's the temp needle is almost down to the "C". My first thought was that the thermostat was stuck open. I replaced the thermostat and the problem is still there. Where do I look next?

[jcclark]

Replace the sending unit, for the temp gage.
It's mounted on the engine somewhere and has a wire
connected to it. They usually don't cost much and are easy to
replace-so I'd do that first.
I have seen them go bad.

[bakguns]

I give it a try. Thanks.

[bakguns]

I borrowed a temp gun from work and the engine operating temp is fine. I will have to look into replacing the temp sender to fix the gauge problems. I just find it strange that the needle stablilizes above the 'C' mark about 1/4 of the way up the scale, but it just isn't in the middle of the band which is where I would expect it to be. In my past experience when a sender fails it either pegs high or low. I appreciate the help.