I noticed lately my 90 vert takes a long time to reach operational temperature? It takes like 10 miles to reach temp--I live in FL so ambient is neglible on cause. Coolant is full and bled.

 

How old is your thermostat? Maybe its sticking a bit? Do you have all your emissions and are functional?

 

Your S5 gauge is not very good...I'd confirm this data with an aftermarket (i.e., real) temp gauge.

 

Doh. I didn't even think of that. If you own a S5 you might was well get a electric water temp gauge.

 

Thermostat is about a year old. I went through 3 before I found one that worked right. 2 Stants and a Motorad, all appear junky when compared to OEM.

I guess the gauge could be inaccurate.

 

check how much heat you are getting to see if you can figure out how warm the car is, if its nice and hot your gauge could be crap.
If it aint that hot you might need another thermostat

 

I've heard of people having real problems with anything but OEM for the thermostat. What do you have installed now? Search t-stat or thermostat and you'll get lots of reading material on the subject.

 

I was thinking thermostat as well. It read 1/2 on the gauge when new and still does, but it wasn't slow to reach temps when new. That was the hottest indication on the gauge I've ever had with a thermostat. Previous thermostats were like 1/4 on the gauge.

 

I disagree.
Typical thermostat failure mode usually results in overheating, not running cold.
Normal running temp on a S5 gauge is 1/2, so if it was reading consistently lower, I'd look at the gauge/sending unit.

As I said before, the S5 water temp "gauge" is more of an idiot light than a proper linear gauge and you should get better data (aftermarket H2O gauge) before doing anything.