On my FZ I would only have 2 bars, but this is in the colder weather. It would get up to three when I set in traffic. After changing my coolant over to Engine Ice, I can sit in traffic and it wont go up to three. However on the trip back with some bad gas and idle issues I got back up to three and saw 4 once.
On the back of the Engine Ice bottle it says it will lower coolant temps up to 50 degree F.
As far as gauges, Im going to install a small voltmeter on my bike since I know we has a low voltage out put and I am running various electronics on my bike now. Oil temp would be interesting, I put one on my Z-28 and I was amazed at how much longer it takes oil to heat up as compared to the coolant get up to temp. I would interested in adding a oil temp gauge, but I would have to do some investigation into a small clean looking gauge, and where to mount it.
-bryan