actron read 75 on engine start. the needle first moved at 90.it went up one needle thickness at100. at 120 it was 1/8 scale. at 130 up to 1/4.
at 140 just above 1/4. at 160 it was under 3/8. 170 at 3/8 177 just over 3/8.
at 185 between 3/8 and 1/2.
192 was 2 needle thickness under 1/2 and stopped there.

ambient was appx 75.
at this time I added a blanket over the grill,under the brush guard and waited.. it cycled from 192 to 194,never higher, in gear idling. for appx 10 min.
killed eng. temp drifted 195 to 201. heat soak.
pulled blanket,started, drop to 194. ran 2000 to 3000it cycled 185 to 188.
the needle was two thickness down from 1/2 and I could see tiny movement from 194 to 188

so it basically reads from 90 to 195 with fair linearity,bottom to almost half way up,but never hits 1/2.
max temp was 201 with eng off.

 

I think it would be interesting if we all did that and recorded where the needle is at different temps. Some of us the norm is when the needle is between 1/2 and 3/4 and some below half. I'll see if I can do a reading this weekend then post it.